Tracking Device

...Not exactly...

"I've lost people before, so when I care about someone, I put a tracking device on them."

— John Reese, Person of Interest

A tracking device is a piece of Applied Phlebotinum that broadcasts its location, and is used to follow the individual or vehicle it's been secretly planted on. Occasionally the individual discovers the device and uses it to lead the trackers on a Wild Goose Chase.

Tracking devices can also be intentionally used by characters on the same side to keep tabs on each other, so that if somebody gets kidnapped, his friends will immediately know where he is. Of course, a bad guy who happens to find a tracking device used for this purpose could easily use it as a Red Herring.

Most tracking or surveillance devices depicted in fiction are so small that they cannot include important components such as a power source, antenna, microphones, etc. This used to seem like magical tech back in the day, but as Technology Marches On with the advent of mobile phones that allow tracking by cell tower, and USB Pen Drive-sized GPS trackers, extremely miniature tracking devices are rapidly becoming Truth in Television. Indeed, it probably won't be long before any tracking device that isn't miniscule qualifies as an Incredibly Obvious Bug, if it doesn't already.

Compare the Sub-Trope Tracking Chip, when a tracking device is implanted.

For the magical equivalent, see the Tracking Spell.

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Examples:

Anime & Manga

• In Count Cain, Cain's earring works like this in a steampunky kind of way, being made of a special stone that causes a larger piece of it to resonate whenever in proximity.
• In the second half of Cross Ange as the remnants of the Norma have restarted Libertus and the 5 pilots who were either captured, saved, or otherwise swayed over to Embryo's side and given Ragna-mail in which to chase their former teammates, Mei somehow manages to have devices planted into each one, which in their case, not only allows her comrades to locate Embryo's base of operations, but to also lay low as long as their side is unable to engage directly in combat.
• Eden: It appears all robots have a tracking device as standard equipment. And they know it's there, because A37 and E92 intentionally break off their transmitter antennas so they can't be found or followed when they take Sara to a place where they suspect she can be raised safely.
• Ghost in the Shell has tracking devices which can be fired out of pistols. In both the movie and the show, Togusa fires one out of his revolver to track a car.
• Early in Magical Girl Lyrical Nanoha ViVid, after Hegemon Ingvalt walked away in apparent victory, the near-immobile Nove Nakajima contacts Subaru Nakajima and reveals that she planted a sensor on her during their battle, so they can track her down and capture her at any time they want.
• Hanaoka the butler from March Comes in Like a Lion lets slip that he keeps track of Nikaidou through GPS before poorly covering up with an alternate explanation as to how he's able to find his young master so easily. Played entirely for laughs.
• Used in the summer camp arc of My Hero Academia — as the Nomu that has been chasing them is recalled by the villains, Yaoyorozu and Awase manage to create and plant a tracking chip on it. She is later able to make a device that can track said chip; the police use it to find the villains' hideout.
• Both the heroes and villains use these in Science Ninja Team Gatchaman. Finding or evading them are plot points in several episodes.
• Yu-Gi-Oh! OCG Structures: Yami Kuroda is overprotective of his sister, Tsukiko. When she tries to have some alone time with her crush, Shoma Yusa, Yami follows them and reveals he put a tracking device in her bag, which pisses her off.

Comic Books

• Astro City:
  • In "Justice Systems", mob boss Dominic Forgione plants a tracker on attorney Vincent Oleck's car to follow him even as Vincent's family flees the city.
  • The Blue Knight marks his targets with a small red crosshair that allows him to track them wherever they try to hide.
  • The employee badges for Honor Guard's call center have a tracking device in them as an anti-kidnapping measure.
• Batman: Often used by Batman. If he doesn't want them to know who's tracking them, they're small, black, and anonymous. Most of the time, though, he does want the target to know; that's when he breaks out the ones with the bat logo or that are shaped like a bat.
• Black Widow: Black Widow's gauntlets can fire tracking devices. They were inspired by Spidey's web-shooters In-Universe.
• Button Man: When the Voices organize a thirteen-on-one game against Harry, they plant a tracking device on Harry so that their own Button Men can stay on top of him at all times. It turns out to be inside a tooth that he had recently had fixed.
• Futurama: Fry has a tracking device stuck up his nose as a result of a bet he and Bender once had. Bender uses it to find the Professor in Fry's body when he's abducted by Wernstrom.
• Horizon: Zhia, Mariol, and Coza track the signal from Finn's beacon to a house in Iowa. It's ultimately discovered in the corpse of a human.
• PS238: Moon Shadow has some to stick onto things, given by the Revenant, and Zodon has a homing beacon in his floating chair that he's in, all the time. Which isn't actually there. It's in Tyler's decoder ring.
• Rivers of London: In Cry Fox, Abigail Kamara and DC Sahra Guleed are fitted with ankle bracelets after their abduction by a group of wealthy people for a round of Hunting the Most Dangerous Game. Abigail steals a letter opener and some wires so they can remove their trackers and dump them in the woods to mislead the hunters, but it turns out there's another tracker hidden in the handle of the letter opener.
• Spider-Man: Commonly used by Spider-Man, usually ones with a "spider" theme or mark. It was a Spider-Man comic strip that led to the invention of electronic tagging.
• Supergirl: In The Killers of Krypton, as Supergirl's ship is being repaired on planet Mogo, Empress Gandelo's minion C'Zal hides a tracking device aboard her ship which lets Gandelo track Supergirl through the galaxy.

Fan Works

• The Marauders in The Rigel Black Chronicles start selling "teacher trackers", intended to be stuck to a teacher's clothing so that enterprising students can avoid them. Draco becomes suspicious of "Rigel's" frequent brief bathroom visits and uses one to try to work out what's really going on, but is confused when the tracking map shows multiple hits at once (due to Harry's Time Turner usage, which was also the reason she kept ducking away for a minute). It saves Harry's life when she's kidnapped and Draco is able to track her down.
• The Secret Return of Alex Mack: After Alex first visits Bruce Paine (her universe's Batman), she has Colonel O'Neill check her, because she just knows that he'll have bugged her.
  O'Neill: Yep, you were right again, Tera. One tiny little bat-shaped bug, right on your boot.
  Terawatt: Yeah, the other Batman did that to his girlfriend, and he even trusts her. So I figured he’d tag me the first chance he got.
  ...
  Alfred: It appears that Terawatt does know you surprisingly well, sir.

Films — Animated

• By way of a translucent red stud on the back of Emmet's leg, The LEGO Movie utilizes this trope. Early on in the film, Emmet gets shot in the back of the leg. He himself doesn't see exactly what he was shot with until somebody asks "What's on his ankle?" Cue Oh, Crap! moment.

Films — Live-Action

• The Adventures of Buckaroo Banzai Across the 8th Dimension: There is apparently one of these on the Oscillation Overthruster (or possibly Penny Priddy), as Buckaroo uses a signal detector to find her inside Yoyodyne.
• Aliens: Corporal Hicks gives Ripley a wrist mounted tracking device. Ripley later gives it to Newt. Near the end Ripley uses the signal to find where Newt is only to find it lying on the floor after being torn off accidentally or deliberately by the xenomorphs. Ripley breaks down in tears, but fortunately Newt is still close enough that Ripley hears her when she screams.
• In The Andromeda Strain, the four scientists (Hall, Dutton, Leavitt and Stone) can be tracked by the first letter of their last name on the electronic diagram, anywhere in the Wildfire complex.
• The Art of War: Shaw suspects that Fang has a tracking device on her clothes and makes her take it all off and throw the clothes out the window of their car. Needless to say she is not happy. Later Shaw finds a tracking sensor and realises he is the one who has the tracking device implanted under his skin by a doctor working in league with The Mole, who 'accidentally' injured him during a basketball game.
• The Avengers (1998): Steed gives Mrs. Peel a set of boots with an implanted "micro-tag" (radio homing signal). He later uses it to locate and rescue her.
• In The Best Offer, a tracking device is planted in the protagonist's car, so the caper team knew when he was approaching.
• Brannigan: The police plant a magnetically attached bug on the vehicle of the mob lawyer used to make the ransom exchange, but he finds it and plants it on another vehicle while stopped in traffic. However, Brannigan has planted a second bug inside one of the bundles of ransom money.
• Cliffhanger involves a mid-air heist of several cases of thousand-dollar bills, but things go wrong and the crates are dumped in the Rocky Mountains. Fortunately, they have tracking devices attached (in case of a plane crash) so the villains kidnap some mountain rescue climbers to help track them down, setting up the plot. At one point, the heroes put a tracking device on a rabbit to send the villains off on a false trail.
• In The Dark Knight, Batman and Commissioner Gordon use low-level radiation to contaminate bills used in drug buys, in order to track the money through the mob's money laundering system. They somehow figure it out, and remove all their money from the bank vaults except the radioactive bills.
• The Dark Knight Rises:
  • Classy Cat-Burglar Selina Kyle steals the pearls that used to belong to Bruce Wayne's mother, but there's a tracking device in them that enables Bruce to find her and take them back (in payback, she steals his car).
  • After Gordon is captured by Bane's men, he throws himself into the Absurdly Spacious Sewer to escape. Bane puts a tracking device in the pocket of the mook who let him escape, kills him, then throws the body into the sewer after Gordon to find out where he ends up.
• The Da Vinci Code: Langdon has a tracker placed on him while in the Louvre due to being suspected of murdering Saunière. Sophie covertly removes it and throws it out a window onto a passing truck, sending the police chasing after it and letting the two investigate in peace.
• DC Extended Universe:
  • In Batman v Superman: Dawn of Justice, Batman shoots a tracking device on the truck Lex Luthor's mooks use to smuggle Kryptonite into Metropolis, then chases them to get it. He gets stopped by Superman in the chase, but he's still able to track the truck down up to LexCorp headquarters later on.
  • In Justice League (2017), Bruce Wayne puts a tracking device in Arthur Curry's jacket when they first meet in Iceland, but it becomes pointless because Curry discards it to swim away in the ocean.
  • In Aquaman (2018), it turns out a bracelet Orm had given Mera is a tracking device, allowing his commandos and Black Manta to locate her and Arthur Curry. After Black Manta clues Arthur in to the tracking device, Arthur tells Mera and she smashes the bracelet.
  • In Zack Snyder's Justice League, Silas Stone uses lasers on the Mother Box he used to rebuild his son Victor as Cyborg and perishes in the process. At first, it's thought that he sought to destroy it, but in reality, he did so to superheat the Box so that the Justice League will be able to track its heat signature via Bruce Wayne's satellites and find Steppenwolf's lair before it's too late.
• Dope: Malcolm gets hunted down by a gangster who wants the drugs he has with a "find my iPhone" app. He realizes this before long and leaves the phone on the bus to get away.
• Escape from New York has two of them.
  • Snake is given a tracer. When he pushes a button his position can be tracked for 15 minutes.
  • The President is wearing a vital signs bracelet that broadcasts a "sig pulse". Snake is given a device that can home in on the signal, showing direction and distance to the device.
• In Escape Plan, Ray Breslin's friends inject him with a tracking device so they could find out where the top-secret prison he's being taken to is. Unfortunately, Ray's captors surgically remove the tracking device and destroy it before he goes very far with them.
• The Family Plan: At first the villains tail Dan with a tracker they put on his minivan. He discovers this and puts it on another guy's car to throw them off.
• James Bond:
  • Bond plants one in Auric Goldfinger's Rolls-Royce in Goldfinger. Felix Leiter later homes in on the smaller one Bond is carrying to locate Bond, who meanwhile has planted the device (along with a message detailing Goldfinger's plan) on a gangster heading for the airport, in the hope that Felix will pick up the gangster for questioning and find the message. Unfortunately, instead of going to the airport the gangster is murdered and put into a car compactor, killing the signal.
  • The Man with the Golden Gun: Mary Goodnight wears a homing device as a button on her clothing. MI6 uses it to locate her after Scaramanga kidnaps her. Ironically, she's kidnapped while trying to plant a similar device in Scaramanga's trunk, only to end up there herself.
  • Never Say Never Again: Fatima Blush plants one on Bond so her electronically controlled sharks can home in on him.
• Life (2017). The crew of the International Space Station have tracking devices on them, and at one point discover they can track the creature as well because it's swallowed a tracker after eating one of the crew.
• The Man from U.N.C.L.E. (2015):
  • In the first part of the movie, Napoleon Solo realizes the KGB has tracked him to his meeting with Gaby Teller. The bug was slipped into his suitcase by a border guard, while Solo was looking at Kuryakin who was carrying out an Incredibly Obvious Tail.
  • When Solo is forced to work with Kuryakin, he gets annoyed when his bug scanner finds Soviet-made bugs in his telephone and all his clothes. Solo goes to confront his partner about this, only for Kuryakin to hand over all the American-made bugs Solo has planted on him.
  • Used for Unresolved Sexual Tension when Gaby Teller says the bug strapped to her garter belt isn't working, so Kuryakin has to put his hands up her skirt to fix the problem.
    Gaby: What are you doing down there?
    Kuryakin: Trying not to get lost.
    Solo: [walking in on them] All turned on now?
  • And all this becomes a Played for Drama Chekhov's Gun shortly afterwards when Gaby blows Kuryakin's cover, knowing that he's listening in on the conversation and will have a chance to get away. Kuryakin then tracks Solo to where he's being held prisoner — turns out he didn't find the bugs in his shoes.
• Marvel Cinematic Universe:
  • Spider-Man: Homecoming: The suit Tony Stark gave Peter has a tracking device on it, which Tony naturally named "Baby-Monitor Protocol". Peter and Ned manage to hack the suit and turn it off.
  • Avengers: Infinity War: Since Vision signed the Sokovia Accords in Captain America: Civil War, he has had a locator implanted in him. This is a problem when Banner returns to Earth warning of Thanos's arrival, since Vision's powered by the Mind Stone, one of the six Infinity Stones that Thanos needs to wipe out half the universe. It's then revealed that the reason Vision turned off his tracker is so no one knows he's pursuing a romantic relationship with Wanda Maximoff.
  • Ant-Man and the Wasp:
    • For participating in the airport battle in Captain America: Civil War, Scott Lang has been placed under house arrest, with an ankle monitor being used to enforce it. To sneak Scott out, Hope sticks the monitor on an enlarged ant that has been "programmed" to go about Scott's daily routine.
    • Hank adds a tracking device to his lab, which works until Ghost deactivates it. Then he get a second one, so a swarm of ants provide directions by forming arrows in the air.
• In The Matrix, the three Agents implant a literal (robotic) bug in Neo's body that they plan to use to track him. Luckily, the Rebels detect it and painfully extract it before discarding it in the street.
• Mission: Impossible Film Series:
  • Mission: Impossible (1996): During the op that starts the film one of Ethan's team members tags the man they intend to steal from later in the night with a tracker that allows them to keep track of where he is in the building even when he's off camera.
  • Mission: Impossible – Ghost Protocol has the target being given papers impregnated with a unique radiation signature (in case he's smart enough to throw away everything else, they can still track him). The only problem is that Ethan Hunt needs to keep the target in visual range, which is nicely ironic when he ends up chasing the target through a zero-visibility dust storm in Dubai. Ethan uses the tracking device to manoeuvre his car into the path of the oncoming vehicle, leaping out moments before the cars crash into each other.
  • Mission: Impossible – Fallout
    • The IMF team are forced to break Rogue Agent Solomon Lane from his prison convoy. He's been implanted with a Tracking Chip that they first block, then remove and place on a drone copter which is then flown off elsewhere. Turns out they simultaneously planted their own Tracking Chip in Solomon Lane, so they can reacquire him if he escapes, which he does.
    • Ethan Hunt is running across London after the villain who is wearing a Tracking Device with Benji guiding him. Unfortunately Ethan has to run up onto the roof of St Paul's Cathedral to escape some people chasing him, but Benji doesn't realise this because his map isn't set on 3D. Hilarity Ensues as Benji gives directions that don't match with reality.
• Used to hilarious effect in The Naked Gun, where Nordberg fails to attach the tracking device, rolls down a hill, and ends up underneath Drebin's own car — "we're right on top of him now!"
• New Town Killers: Wondering how Alistair and Jamie keep finding him no matter where he runs, Sean checks every thing he is carrying and discovers Alistair has planted a tracking device in his leather jacket. He manages to slip the device on to a similar looking boy in the club, resulting in the other getting a severe kicking from Alistair.
• No Country for Old Men: The protagonist is pursued by various factions after taking a bag of money from the aftermath of a drug deal gone bad; he eventually realizes that there was a tracking device in the money and disables it, but by that time, the antagonist is already in hot pursuit.
• Patient Zero (2018): A tracking device is discovered in "Pete Townshend". It appears to have a blinking and beeping green light on it.
• In Ransom, the kidnapper orders Mel Gibson's character to jump fully-clothed into a swimming pool to deactivate any such devices. The police are able to follow him to the ransom drop-off anyway.
• Razorback: The eponymous giant razorback is shot with a tracking dart. When a signal is picked up, a posse goes racing off to its location only to find an ordinary boar shot with a similar dart. When the signal goes off a second time to show the giant razorback is close, no one is interested as they're busy getting drunk in the pub.
• Red Dawn (1984): The Soviets capture one of the American guerillas and force him to swallow the tracking device. Unfortunately, the spetsnaz team they have following him gets ambushed, and their homing beacon points directly at the traitor.
• Runaway: When the police arrest the girlfriend of Mad Scientist Doctor Luther, they put her in a scanner and she has to strip off as they find one tracking device after another hidden on her clothes. Later when they're transporting her to a safehouse, Luthor sends autonomous robot vehicles to blow her up, and they turn out to be homing in on the one tracking device that they missed.
• Johnny Five from Short Circuit has a tracking device that he tosses into the bed of a passing pickup truck.
• Star Trek Beyond: When our heroes are trying to locate where their crew is being held prisoner, Spock states that he can locate Uhura by scanning for the unique signature of (harmless) radiation emitted by the Vulcan necklace he gave her. Everyone gives him a funny look.
  McCoy: You gave your girlfriend a tracking device?
  Spock: [Oh, Crap! face] That was not my intention.
• Star Wars:
  • Attack of the Clones: Obi-Wan plants one on the Slave I so he can follow Jango Fett.
  • The Millennium Falcon gets one in A New Hope, leading the Death Star to the rebel base at Yavin 4.
• In the climax of Steel Rain, Eom has to courier the code generator that will enable Ri Tae-han to launch North Korea's nuclear arsenal. However the code generator has been removed and a tracker has been installed so an airstrike can be called down when it's triggered. It uses a powerful radioactive source for this, so Eom is advised not to wear it, but he points out it's not like he has to worry about radiation killing him.
• Swamp Shark: The staff of the Gator Shed planted tracking devices on their captive alligators to keep track of them. Since the shark attacked, and they believe, at the gators, they decide to use the trackers to find it. They track them out into the bayou... and find the tracking devices in the water. The shark attacks as they're hypothesizing where it might be.
• In Thief (1981), Frank finds a cigarette pack-sized tracking device behind the bumper of his car. The Chicago police are following what they think is his car driving out of town to a robbery, but they're following a Greyhound bus bound for Des Moines, with the tracker in a package in the cargo hold.
• In Underworld: Blood Wars, Gregor shoots David in the gut with a drilling bullet that burrows deeper into his body and is also a tracking device. Fortunately, Selene manages to cut it out of him. Gregor and his team burst into their safehouse only to find them gone and the discarded bullet in a sink.
• In Unknown (2006), a tracker is planted in the bag that holds the ransom money, so Police could track down the kidnappers. They use a cell phone with a Viewer-Friendly Interface displaying the target as a red button. However, the kidnappers smelled a rat and dropped the bag underway.

Literature

• In Axiom's End, Cora Sabino has a tracker implanted by the alien being Ampersand that allows monitoring of her location and health while she acts as an interpreter.
• Ai no Kusabi has "Pet Rings" which all have built-in tracers to track a pet's whereabouts. One pet in particular finds this out the hard way.
• Children of Dune: When Alia sends Buer Agarves on a diplomatic mission to Stilgar, she conceals a homing signal in the new boots she gives him so her forces can follow him and capture Stilgar.
• Since The Dresden Files is from the viewpoint of a wizard detective, tracking devices don't feature much. (Usually, Harry will use items to focus his mind for tracking spells, have "dewdrop faeries" follow the target, or even follow behind them himself.^note In one notable subversion, he subcontracted to another Private Investigator. Nobody involved expected that.) However:
  • Small Favor has Harry realize that a small 'silver oak leaf' on a chain, provided to him by the Summer Court as a token of an owed debt by the Court towards him, is being used by Summer's "hitmen" to figure out where he is.^note And why is Summer gunning for him when it owes a debt? The Winter Court effectively assigned his current case, and the two courts tend to be automatically opposed. When he figures this out, Harry uses the 'Little Chicago' model to make the leaf think he's appearing wherever it get close to on the model, ties a catnip bag and a rubber band to it... and lets his cat Mister play. By the end of the book, Harry has used the obligation up, and the leaf vanishes (or is reclaimed), so whether or not it still can be used for tracking after this is somewhat of a moot point.
  • Turn Coat reveals that Morgan received a similar silver oak leaf, to represent a debt from the Summer Court towards him. He's already claimed the obligation by asking Summer to hide him from magical tracking for roughly three days, so that he can figure out who killed a fellow White Council wizard and set him up to take the fall. Harry realizes that Exact Words might be in play: Morgan won't be tracked, but the leaf (which is still around, and belongs to the Summer Court anyway) can be tracked... and the Court can freely tell anyone that thinks to ask the right questions... Cue a face palm from Morgan for not being paranoid enough.
• The Executioner: In Rain of Doom, Able Team discover a plot to attack Washington D.C. with chemical weapon rockets guided in with homing beacons carried by Unwitting Pawns. Before they have had a chance to smuggle the beacons and rockets to the United States, Able Team secretly activates one of the beacons in a suitcase carried by the Big Bad and launches the rockets on its location.
• Full Metal Panic!: A captured A21 terrorist has the device implanted under his skin, so our heroes use a microwave oven to destroy it (holding down the door safety button so the microwave will work with the door open). Unfortunately, he then pickpockets a mobile phone from Kaname and signals his location that way.
• The Ganymede Takeover: Gus Swenesgard is about to be skinned alive (literally) by his alien overlord after he inadvertently let some powerful weaponry fall into the hands of La Résistance. Fortunately, he blurts out that he planted a micro-transmitter in the hair of a reporter who was going to interview the rebel leader.
• Is It Wrong to Try to Pick Up Girls in a Dungeon?: When Sanjouno Haruhime is enslaved by Ishtar, she wears a collar that allows Ishtar and her minions to know where she is at all times.
• In The Mouse Watch, the titular heroes give their new recruit Bernie a hair clip that contains one of these. She eventually tricks Dr. Thornpaw into putting it in his pocket.
• Mrs. Smith's Spy School for Girls: Bronwyn a.k.a. Suzie gives Abigail a tracking device when they first meet. They also plant another one on her person later on.
  • Mrs. Smith's Spy School For Girls: Double Cross: Poppy Parsons developed a smart fabric that tells you if you're too hot, too cold, hungry, and whatever else. It also tracks your location. Abby and Poppy use it to track Owen Elliot's location to a derelict plantation house in Hawaii.
• Rebuild World:
  • After Akira is seriously impressed by Sheryl clearing a game he could barely even start, he gives her his phone, which had been hacked by his Virtual Sidekick Alpha. Thus, when Sheryl is held in a Hostage Situation, the phone is used as this to allow Akira to find and free her.
  • After the Mad Scientist Yatsubiyashi turns Tiol into a Tragic Monster while Playing with Syringes, he keeps track of Tiol using one of these planted inside his body. He loses contact once Tsubaki hacks into Tiol's systems, prompting Yatsubiyashi to launch an expedition into the ruins with the excuse of running a for-profit field clinic.
• Danielle from Saving Max is given an ankle bracelet to keep her within a fifty-mile radius.
• Shade's Children: The Overlords implant human children with tracers to track down any who escape the Dorms. Some still manage to remove it however.
• In Isaac Asimov's science fiction novel The Stars, Like Dust, the protagonists have stolen a military starship from the enemy empire. Unfortunately for them, every such ship is fitted with a device which allows it to be tracked across interstellar distances. Had they stolen an ordinary freighter, it would have been far more difficult—or even impossible—to track them.
• In the Stephanie Plum series, Ranger routinely plants tracking devices on Stephanie, her car, etc. In one book, she and Ranger are going through her purse and find three. Only one was Ranger's.
• In The Stranger Times, Grace asks Ox to set up a tracker on Stella's phone in case she runs away again. It comes in handy when Stella is kidnapped and the group needs to find her. Ox also arranges to plant a tracker on a person of interest's car in the second book.
• In Time Enough for Love, Lazarus Long Time Travels to meet his family when he was a child. Due to a miscalculation, he winds up in 1917 instead of 1920, just in time for the United States to get into World War I. Prior to leaving, he was unknowingly implanted with a tracking device by his family of the future, which comes in really handy when he gets shot in battle and has to be rescued.
• Vorkosigan Saga: In Komarr, Miles briefly thinks he'll be able to get a lead on the villains when they steal his Auditor's seal, which has a tracking device embedded in it. Unfortunately, they know about the device, and almost immediately flush the seal down the toilet to serve as a particularly messy Red Herring.
• The Witch of Knightcharm: Lauren secretly implants a magic spell in Emily's neck which allows Lauren to track Emily's location. This is a problem, because Emily is secretly trying to undermine the evil Wizarding School they both attend, and she can't slip away to sabotage it while Lauren is keeping an eye on her.

Live-Action TV

• May be one of the most used devices in the series Alias.
• Altered Carbon: Detective Kristin Ortega is illegally using Hawkeye software to keep tabs on Takeshi Kovacs. Turns out in the pilot episode she slipped a bug under the AddBlocker she put on Kovacs' neck to prevent him being overwhelmed by the Advert-Overloaded Future. When Kovacs is captured and taken to a torture clinic (which is shielded against transmissions), his captors search him and remove the bug, which they see as evidence that Kovacs is an undercover police officer (he's not). After escaping, Kovacs leaves the bug in the clenched fist of a headless corpse, middle finger raised, for Ortega to find.
• Arrow: Oliver Queen has a Trick Arrow laced with "particulate nanotechnology" (apparently something he picked up from A.R.G.U.S), enabling it to be tracked by GPS anywhere in the world thanks to a software program written by Felicity Smoak.
• Batman (1966):
  • In "The Joker's Flying Saucer", when Alfred is forced to help the Joker assemble the flying saucer, he puts several Bat tracking signals inside the saucer so Batman can learn its location after it lands.
  • In "Batman Stands Pat", the Mad Hatter is kidnapping members of the jury that convicted him and stealing their hats. Batman has Alfred plant a Bat Homing Transmitter in the hat of the last juror so he can trace the Mad Hatter's location when he steals the hat.
  • In "The Penguin Declines", the female villain Venus deserts the Joker and falls in love with Batman. However, the Joker anticipated that she would do so and planted a tacking signal in her shoe. He later uses the signal to find Venus's location and send the Penguin (?!) to seduce her.
• Better Call Saul: Mike realizes he's been bugged after his attempt to snipe Hector Salamanca is interrupted by his car horn going off. It turns out that Gus Fring had managed to get his temporary car and his regular car bugged. Mike manages to turn the tables on Gus by buying an extra tracker, then draining the original tracker so that Gus will send someone to replace it. The guy sent to pick up the tracker instead picks up Mike's active tracker. Mike follows the tracker, eventually ending up at Los Pollos Hermanos. He sends Jimmy inside to spy on the bag man. Unfortunately, Jimmy's attempt at spying is clumsy enough that Gus realizes Mike has caught up to him. So he has Victor take the tracker away from the restaurant, leaving it inside a gas cap in the middle of the road with a ringing cell phone ready for Mike to answer when he locates it.
• Black Mirror: In "Metalhead", the Killer Robot Dogs shoot shrapnel bombs; not to kill their prey, but rather to tag them with hard-to-remove tracking devices, the better to hunt them down with. The protagonist is able to remove the tracker and disable the Dog that's been chasing her throughout the episode, but its last act is to fire a bomb to tag her once more. Realizing that there's no escape, she kills herself rather than suffer the same ordeal again.
• Blake's 7:
  • In "Shadow", a radioactive element is added to the titular drug Shadow, so the local organized crime boss can track all the addicts. No-one cares if the addicts get cancer because they inevitably die from the drug.
  • In "City at the Edge of the World", Vila is bullied into going on a solo mission, and is told to swallow a tracer. But Vila resents his colleagues' actions so much he palms it instead. When he later goes missing...
    Avon: Orac, can you give me a precise fix on that tracer?
    Orac: Of course I can!
    Avon: Where is it, then?
    Orac: Under the box which is ten centimeters from your right hand.
  • In "Traitor", the Federation releases a prisoner so that he'll make contact with the rebel unit that sent him to infiltrate their base. He's unknowingly swallowed a tracer, and they launch missiles on his position when the signal shows he hasn't moved for a while, assuming that's the rebel base. It turns out that he was just waiting at a rendezvous point, and the rebels were waiting for the cover of night before going to collect him.
• Breaking Bad:
  • As part of his off-the-books investigation into Gus, Hank enlists Walt's help to plant a tracking device on Gus's car. Walt manages to tip off Gus, who then only uses the vehicle to drive between home and the restaurant.
  • Walt later finds a tracking device on his own car.
• Buffy the Vampire Slayer:
  • The Initiative shoot Spike with a tracking device which Xander recognizes because it blinks for no apparent reason. Well, maybe that comes in handy when tracking vampires in the dark.
  • Willow's oft-used "locator spells".
• The title character of Chuck wears one in his wristwatch so (theoretically) his handlers can always find him.
• The City Hunter: Young-ju bugs the City Hunter during their first fight. Yun Sung later bugs the stolen 2 million dollars in Kim Jong-shik's house.
• The Company You Keep:
  • In "Against All Odds", it turns out that Birdie had used a tracker to know where her daughter Ollie is. Later on, Ollie puts this into Daphne's purse instead, which lets her movements be tracked for Charlie and Birdie to discover later. This reveals Daphne met crime bosses all around the US.
  • In "The Art of the Steel", it turns out that Birdie has placed a tracker on her dad Leo's phone so she can tell where he is, since his dementia might make him get lost.
• Cowboy Bebop (2021):
  • In "Callisto Soul", Faye Valentine steals the Swordfish (along with Ein) but is quickly tracked down by Spike and Jet even though she deactivated the tracker. Turns out Spike has more than one on his personal ship.
  • In "Galileo Hustle", Faye's "mother" Whitney has taken refuge on the BeBop from her psycho husband. Jet finds a tracking device hidden in her wedding ring, so Spike and Jet take the wedding ring with them to misdirect the mooks sent after her, leading them being mistaken for a gay couple when they start arguing Like an Old Married Couple while wearing the ring.
• Daredevil (2015):
  • In Season 3, Wilson Fisk is under house arrest and has to wear a leg monitor that will sound an alarm if he goes outside his designated area. However Fisk has had a secret room constructed underneath his bedroom from which he can control his criminal empire, making it look as if he's never left the room. Whenever he has to go elsewhere, he has a woman who works in the secret room wear the monitor instead (she's being coerced into working for Fisk, so she's more of a prisoner than he is).
  • In Season 2, the Hand abduct a group of people who have been saved by Daredevil. Fortunately one of them is Turk Barrett, who is now on parole for crimes he committed as an associate of Fisk's in season 1. Karen activates Turk's ankle monitor so that the police will be summoned to their location, which also allows Matt to track them down.
• In Day Break (2006), Buchalter and Fencik plant a device under Hopper's car so they won't lose track of him. When Hopper finds out, he sends them on a Wild Goose Chase.
• Extant: All the astronauts have one stuck to the roof of their mouth. It's supposed to be used to gain data on their vitals but it can also track locations.
• Ginny and Georgia: Georgia puts a tracker in Austin's watch when he's with his dad, whom she doesn't trust.
• In Healer, most of the tracking devices are very small and well disguised like the ones in Jung Hoo's watch and necklace. The tracking devices he attaches to cars are rather conspicuous things about the size of a nickle with a small blinking red light. This is probably just so that the audience doesn't need it spelled out for them what he's doing every time he uses one.
• Intergalactic: All of the prisoners have them implanted in their bodies, and they're painfully removed on Pau Rosa when they put down there so Commonworld authorities can't find them.
• JAG: Used by Clayton Webb in his first dealing with Harm and Mac to track their car in "We The People". However, they're savvy enough to leave it.
• When the war arc of Kamen Rider Build starts, Gentoku had tracking bracelets made for Sento and Ryuga that contain personal GPS to keep track of where they are and a two-way communication link so that Gentoku can reach them at any point. Sento figures out how to remove his bracelet, but Ryuga retains his bracelet since he is willing to fight in the war if it means clearing his name for his and Kasumi’s sakes.
• In the Leverage episode "The Stork Job", Hardison reveals when Parker goes off on her own that he put a GPS tracker in her shoes. It's implied that he keeps tabs on the entire team this way all the time. He also often uses the various magical earpieces that they have for this purpose as well. Fitting this trope those devices are sufficiently small that there is no way that they could ever really work.
• Line of Duty: In Series 6, it turns out that the Chief Constable ordered trackers placed on all AC-12 vehicles, letting them quickly locate Jo and Kate after they go on the run, as they're driving one which Steve provided with keys for an emergency.
• Tracking fobs play an important role in The Mandalorian, used by Bounty Hunters (including the title character) to track their targets. Each one is capable of homing on a target with great accuracy as long as they've been programmed with enough data, called the "chain code," and returning the fob is the customary way of saying the hunter has released his bounty to someone else's custody.
• In the Miami Vice episode "Tale of the Goat", Tubbs attaches a tracking device to the underside of a truck he's riding in. It falls off, and when Crockett tries to follow him, he finds the device lying in the road.
• Monarch: Legacy of Monsters: In his retirement at a Monarch-run Gilded Cage, Lee Shaw is forced to wear an electronic tracking anklet at all times. Justified, as not only was the anklet provided by a covert group who have an unlimited spending budget, but this part of the series takes place in 2015, when tracking devices were becoming more and more real, and the actual anklet has a rather blocky electronic box on it.
• Often used on NCIS, for the agents themselves to be rescued or just followed, or suspects or criminals.
• NCIS: Los Angeles has a tracking spray variant that's used to follow a terrorist to his hideout.
• The Night Agent: Rose had one placed on her, it turns out, letting assassins Dale and Ellen find her.
• Once Upon a Time: Bo Peep, who was a warlord in the Enchanted Forest, "branded" her victims with magic, which allowed her to use her shepherd's crook to track her victims. In Storybrooke, David used the crook in an attempt to locate Anna; while he couldn't get a fix on her, the crook did register her heartbeat, indicating that Anna is still alive.
• The Pact: Anna installs a tracking app to locate the phone of the person who called her for blackmail, which lets her find out her friend Nancy did it.
• Person of Interest:
  • Team Machine usually does this by hacking the mobile phone of the Victim of the Week and using its GPS locator. Finch is quite proud when he hacks an Artificial Limb into giving away its position to every phone repeater it passes. Finch is Properly Paranoid about this himself; it's no surprise when he smashes a $2 million watch given to Team Machine by a grateful billionaire to remove its GPS locator.
  • They still fall victim to them on more than one occasion. Notably Root and the FBI each manage find them at different points. Root with a classical tracking device, and the FBI by a brute force attack on their phone system.
  • Root steals an indestructible Kevlar briefcase, but can't break into it to remove the tracking device. She resorts to using a lamp to short it out, but the former owners are already kicking down the door.
• The Professionals: In "Servant of Two Masters", Cowley has fallen under suspicion of corruption and Bodie and Doyle are ordered to investigate. At one point they are leaning on Cowley's car as he briefs them for their next assignment, causing them to stumble when he abruptly drives off. Bodie then smirks that he got his own back by using the opportunity to plant a 'bleeper' on the car. Cowley however switches cars as a routine precaution, forcing Bodie to follow him the old-fashioned way. The same trick is used in "The Acorn Syndrome", and Bodie barely has time to attach a bleeper to the second vehicle as it drives off.
• The Rising: Neve's last recorded location gets revealed using a tracking app that Katie put on her phone. It turns out that she's not there though.
• Used on an episode of Scrubs so JD can track and avoid the Janitor.
• Search 1972: The Everything Sensor given to agents of World Securities relay a wealth of data to Probe Control, including that agent's location. "The 24 Carat Hit" has Agent Bianco reveal this device's weakness: if any two devices come into proximity, their signals will overlap, blurring their precise location.
• Siren (2018): Maddie gives Ryn a pendant with one inside so they can know her location during "On the Road".
• Star Trek:
  • The commbadges that Starfleeters wear starting in Star Trek: The Next Generation double as trackers.
  • In Star Trek: Picard, Commodore Oh gives Jurati a tracking device which she's actually required to chew before swallowing, causing it to dissolve into her body. When she realises a hostile spacecraft is using it to track them, her first urge is to vomit (she was also Post-Stress Overeating at the time). This has no effect, so she injects herself with a lethal neurotoxin to neutralize the tracking agent. Fortunately, her colleagues are able to revive her.
• Titans (2018):
  • Dick Grayson tells Donna Troy to track Kory Anders, so she throws a shuriken with a tracker into the back of her car as it drives off, which sends a signal to an app on her mobile.
    Donna: You think you're the only one with gadgets?
  • When Hank Hall goes to meet Jason Todd after he's turned rogue, the latter forces Hank to strip to prove he's not wired, then makes him swim naked across a filthy pool in an abandoned gym. Hank is not happy about it one bit.
• The Twilight Zone (1985): In "Profile in Silver", time travelers such as Professor Joseph Fitzgerald and Dr. Kate Wang are issued with homing devices in the form of a ring. When the homing device is separated from the temporal wrist controls worn by the time traveler, the wearer of the ring is automatically returned to their point of departure. Fitzgerald uses this to send John F. Kennedy forward in time to 2172 so that he doesn't have to be assassinated.
• Used over and over again in Veronica Mars in order to track and find nearly anybody.
• As part of his release agreement with the FBI, Neal Caffrey of White Collar has to wear an ankle tracking bracelet at all times (until his 4-year term is up, anyway). He cannot leave a 2-mile radius of his home (which, fortunately for him, is in Manhattan) except with an FBI escort, and if he tries to remove it without authorization (occasionally given as part of an operation), it sends out a signal.
• The Wire: The opening of "Storm Warnings" is a Hard-Work Montage where we see, among other things, members of the Major Crimes Unit hanging tracking devices on vehicles owned by their latest targets.

Tabletop Games

• In the Battlelords of the 23rd Century supplement Lock-N-Load: The Battlelord's War Manual, the Electronic Tracer Device has an adhesive strip that allows it to be secured to an object, such as a vehicle. It broadcasts a low frequency radio signal for up to 120 hours that can be detected up to 7 kilometers away.
• The adventure included in Champions Organization Book 2 PRIMUS and DEMON notes that PRIMUS (an anti-villain U.S. Government agency) puts a transponder inside all captured supervillain devices to assist in tracking them down if they go missing.
• In Iron Crown Enterprises' Cyberspace:
  • The Homing Device is a constantly broadcasting high frequency transmitter implanted in a living creature (such as a human being). It can only broadcast a few kilometers away.
  • The Arm Sentry is a small device strapped to the arm of guests in corporate areas. It constantly broadcasts its position to the company security computer. If the wearer enters an area they're not authorized to be in, the computer sounds an alarm.
  • The Tracer is a transmitting device that is either worn or implanted. They can be traced over great distances by ground-based or satellites. All corporate and government personnel have these implanted in their bodies so they can be recovered in case they're kidnapped or become lost.
• DC Heroes: One piece of equipment characters can buy is a "tracer", a small radio transmitter that sends out a steady signal that can be picked up by a receiver. It has a maximum range of 5 miles.
• Shadowrun has the AOD (Activate On Demand) tracking signal. It only transmits when it receives a specific coded signal, which means it cannot be detected by standard radio detection techniques except when it is actually transmitting.
• In the Victoriana RPG supplement Faulkner's Millinery and Miscellanea, one possible Complication (drawback) for a magical clockwork limb is a tracer device implanted in it, which allows someone to know where you are at all times.

Video Games

• Ghost Trick: Cabanela fires a special bullet into Yomiel's body, which can be tracked by a modified pocket watch.
• Kingdom Hearts 3D [Dream Drop Distance]: When Sora is eventually captured by the bad guys, they reveal that Master Xehanort can magically track down any "X", like the X on Sora's shirt.
• In Mass Effect 2, after you acquire the Reaper IFF chip, it installs a virus into the Normandy's computer that broadcasts its current location. Which results in the kidnapping of all of your crew except Joker. Kinda makes the Paragon choice in the endgame (to destroy the Collector Base rather than reverse-engineer it) seem the right one: if a mere chip made by the Reapers could outsmart the best AI humans could produce, what would an entire base do?
  • Mass Effect 3 has Miranda plant a tracer on Kai Leng on Sanctuary, leading Shepard directly to Cerberus's main base. The spoiler for 2 is also revealed to be fairly irrelevant. Even if blown up, enough of the base remains that Cerberus undertakes major salvage operations and some degree of indoctrination and so on happens anyway.
• Franziska plants one of these on her incompetent detective partner Gumshoe in Phoenix Wright: Ace Attorney – Justice For All, much to Gumshoe's displeasure.
• In Secret Agent Barbie, Barbie has a gadget which is basically tracking perfume.

Webcomics

• In addition to working as a Mind-Control Device, the iKnow from Commander Kitty can serve as one of these.
  Zenith: What does that beeping mean? Is he getting close?
  Fortiscue: Oh...shucks.
• This strip of Irregular Webcomic!.
• In Rank Amateur, GELF are officially required to wear these. They were generally fitted to GELF even before it became law.
• More like the fun tracking programs you can get for your cellphones to track your friends, Pockets in Tower of God have this option that two mutually registered Regulars can track each other.
• In Yokoka's Quest, Yokoka, Yfa, and Mao are magically tracked using the ribbon weapons that Vivi gives them.

Web Originals

• Lobo (Webseries): Lobo was given this from Stumpy to track down Mudboy the Porkan.
• Whateley Universe:
  • The Whateley Academy student cards can track students with embedded RFID through doorways, because all doorways are equipped with RFID scanners that report who uses them.
  • Tracking devices are also mentioned every once in a while, some made by Whateley students, as well, such as in Original Canon - Imp 5 Head over Tail (Part 2). Others are made by the Academy, like the tracking device that Reverend Englund wanted Sara to wear. Professional Courtesy also mentions them.
  • The Intelligence Cadet Corps deserve special mention, as they get into serious trouble more than once for their indiscriminate bugging of the Bad Seeds... and the Masterminds... and the Literary Club... and some of the teachers who were former supervillains... and their own faculty advisors...[1] It was pointed out to them that the main effect of their spying was to give the potential supervillain students an excellent education in how to avoid being tracked.

Western Animation

• Also played for laughs in Invader Zim, where the "tracking device" turns out to be GIR clinging to the back of Dib's enormous head.
• Played for laughs in an episode of Jackie Chan Adventures. An episode that involves clones of the heroes has Captain Black place a tracking device on one of the Jackies. He starts bragging about it before the real Jackie points out that it's on him instead of the escaped clone. Jackie then forgets to take it off, allowing Jade to track him down.
• Kim Possible sometimes uses various kinds of trackers, including tracking powder (got in the vent system of the building). Wade also has one on Ron, just because.
• The Loud House: In "The Spies Who Loved Me", Carl plants a tracking device (which his dad apparently sawed onto his jacket) on Ronnie Anne’s backpack so they can keep an eye on her without her knowing. However, the device falls out of it when Ronnie Anne takes her skateboard out of her backpack, and gets stuck to a rat.
• Skull Island (2023): The initial antagonists of the series are Private Military Contractors who kidnapped Annie from an Isle of Giant Horrors neighboring the titular island, before she escaped them and ended up with a boat crew, and they all get stranded on Skull Island. The mercenaries' leader Irene is still determined to recapture Annie, tracking her across the island using a remote tracking chip that's hidden in the broken handcuffs still attached to Annie's wrists.
• Space Ghost episode "Homing Device". Before the episode starts Jace puts the title homing device on Blip's collar so he and Jan can always find him. Blip stows away on the Phantom Cruiser when Space Ghost goes to surrender to Metallus, allowing Jan and Jace to follow them.
• 1973-74 Super Friends episode "The Planet Splitter". The Super Friends put microdot homing devices on the remaining 100+ carat diamonds so they can be tracked down after they're stolen. At the end of the episode, Wendy puts Wonder Dog on a diet, them puts a microdot homing device on one of his favorite steak bones so they can track it when he steals it.
• Also in SWAT Kats. Hard Drive and Dark Kat stole the Turbo Kat and used it to commit crimes and frame the heroes. They demanded several bags of money. Commander Feral hid a tracking device in one of them. The bad guys throw away a bag (presumably the one with the tracking device) and, using a device to impersonate T-Bone's voice, said "Nice try, Feral!"

Real Life

• Modern cellular phones have GPS receivers in them to provide locations during emergency calls. Some offer tracking services that allow account holders to keep track of their children, or track a lost or stolen phone.
  • Sadly, these capabilities are also increasingly used for more nefarious purposes.
  • Whether or not turning off the GPS feature of the phone actually deactivates tracking or just hides it from applications on the phone itself (but not from the service provider) is up to the phone manufacturer. In any event, even without GPS, if the phone is communicating at all with the cell system, the phone company can tell the maximum possible distance the phone can be from any given cell tower by measuring the strength of the return signal; the phone must be within the region where the possible locations from each cell tower getting a signal from that phone overlap. In an area with a fairly dense network of cell towers (such as a city), this can typically locate the phone to within a radius of 50 meters or so. Such communications happen regularly even when you're not actively using the phone, so if you really want to hide, put it in "airplane mode" (which supposedly disables all wireless communications) or, if you're too paranoid to rely on that, remove the battery or put it in a Faraday cage.
  • Key finders become more powerful when they transmit not to just one particular phone, but any phone in the vicinity. Apple's AirTag works very well in regions with plenty of iOS devices going around, and the upcoming Google's Grogu would have even wider coverage due to Android's ubiquitous presence. There are safeguards in place to discourage its use by stalkers (warning someone if a new tracker has been following them, audible alarm if it's not connected to the owner's device for a prolonged period), but they can be worked around (eg, removing the speaker and targeting someone outside the ecosystem, since currently, Apple's tracker won't warn Android user) and unlike smartwatches, trackers are far cheaper and can last for a year on a single button battery.
• US vs. Jones resulted in a decision that, within the USA, use of such a device without a warrant may violate 4th amendment rights.
• There are systems that can track stolen motor vehicles. LoJack and Onstar are two of the best known.
• A smaller-scale form of tracking can be used to find a misplaced cell phone by calling it so that it rings or using an app/webpage to make its alarm tone go off and then follow the sound.

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