Comic Books
"This is how they see you. [...] You're their champion. Bigger than life. No wonder the eyeglasses work— nobody would look for you dressed like them!"
Fan Works
Izuku knew from experience that no one expected anything from a quirkless kid, especially one who didn't even stand up to his own bullies. If Izuku Midoriya was ever a suspect for Mastermind, his lack of quirk would instantly clear him of any suspicion. If the police looked past that, then the fact that none of his bullies had died mysteriously in the last year would be brought in as evidence that he obviously "wasn't capable" of being the villain. What the police wouldn't know is that Izuku Midoriya, quirkless deku, was a mask. And if they managed to look past all that? Well, then they were smarter than Izuku gave them credit for and maybe, just maybe, they deserved to arrest him.
Film — Live-Action
"Shola and Polly have gathered a network of domestics such as the world has never seen. While British intelligence listens at keyholes, our people are actually in the room."
— Duke of Oxford, The King's Man
Literature
One of the things about being a quiet girl in a very big house is that you can, if you try, be invisible in plain view, and it was amazing what you could overhear when you were being a good little girl helping Cook in the kitchen by cutting out pastry shapes. There were always delivery boys or men from the estate after a cup of tea, or Cook's old friends just dropping in for a chat. The secret was to wear ribbons in your hair and skip everywhere. It completely fooled people.
— Nation
Hercule Poirot: A vous la parole! Describe this man.
Thora Grey: I can't ... I don't know how to ... He had glasses, I think ... and a shabby overcoat ... [...] He stooped ... I don't know. I hardly looked at him. He wasn't the sort of man you'd notice ...
Hercule Poirot: You are quite right, mademoiselle. The whole secret of the murders lies there in your description of the murderer — for without a doubt he was the murderer! "He wasn't the sort of man you'd notice." Yes — there is no doubt about it ... You have described the murderer!
Thora Grey: I can't ... I don't know how to ... He had glasses, I think ... and a shabby overcoat ... [...] He stooped ... I don't know. I hardly looked at him. He wasn't the sort of man you'd notice ...
Hercule Poirot: You are quite right, mademoiselle. The whole secret of the murders lies there in your description of the murderer — for without a doubt he was the murderer! "He wasn't the sort of man you'd notice." Yes — there is no doubt about it ... You have described the murderer!
Domingo: Most of the time no one asks me for papers. I know the places where they never even bother thinking about asking, anyway.
Atl: Why don't they?
Domingo: 'Cause I'm not important. If I was a superhero my power would be invisibility.
Atl: Why don't they?
Domingo: 'Cause I'm not important. If I was a superhero my power would be invisibility.
"The trouble with you, Peter, is that when you think of a witness to a planetological statement, you think of planetologists. You divide up human beings into categories, and despise and dismiss most. A robot cannot do that. The First Law says, 'A robot may not injure a human being or, through inaction, allow a human being to come to harm.' Any human being. That is the essence of the robotic view of life. A robot makes no distinction. To a robot, all men are truly equal, and to a robopsychologist who must perforce deal with men at the robotic level, all men are truly equal, too."
"It would not occur to Madarian to say a truck driver had heard the statement. To you a truck driver is not a scientist but is a mere animate adjunct of a truck, but to Madarian he was a man and a witness. Nothing more. Nothing less."
"It would not occur to Madarian to say a truck driver had heard the statement. To you a truck driver is not a scientist but is a mere animate adjunct of a truck, but to Madarian he was a man and a witness. Nothing more. Nothing less."
People looked at a rumpled academic and dismissed him as a scholar and a nonentity. They didn't start asking themselves how many knives he was carrying. That would have been silly, and the last thing a Covenant scholar inspired was silliness.
— InCryptid, "Halfway Through the Wood"
Incidentally, while you are correct that the streets of London have ears, it might also behoove you in the future not to take the first cab that comes along. Cab-drivers have ears too, if they choose to use them.
If someone wears garb that's official-looking but unobtrusive, acts as if they belong, and above all doesn't make eye contact, they can go almost anywhere without being seen.
—The Flying Cloud, inner monologue of Jenkins
Live-Action TV
Scorpius: How can I take anything? I'm not strong enough.
Tauza: Bide your time. Gather your strength. Become invisible.
Young Scorpius: Become invisible? I don't understand. How do I do that?
Tauza: A cunning underling can learn much while revealing little. No one pays a beast of burden any heed. Learn to serve without complaint. A good servant draws no punishment and is soon forgotten. The forgotten become invisible. And the invisible are free to seek out their masters' weaknesses.
[Flashforward to an older Scorpius using this very lesson to stab Tauza's eyes out]
Tauza: Bide your time. Gather your strength. Become invisible.
Young Scorpius: Become invisible? I don't understand. How do I do that?
Tauza: A cunning underling can learn much while revealing little. No one pays a beast of burden any heed. Learn to serve without complaint. A good servant draws no punishment and is soon forgotten. The forgotten become invisible. And the invisible are free to seek out their masters' weaknesses.
[Flashforward to an older Scorpius using this very lesson to stab Tauza's eyes out]
— Farscape: Let Sleeping Dogs Lie
See, no one ever thinks about the cabbie. It’s like you’re invisible. Just the back of an ‘ead. Proper advantage for a serial killer.
— Sherlock
Tabletop Games
Most other vampires have no idea that the Nosferatu have such a toehold in human society. Confident that no self-respecting mortal would feed from a Nosferatu, other clans continue to control their politicians and artists and tycoons. These ghouls in turn ignore the "lowly" servants and sanitation workers who hover around them, listening...
— Vampire: The Masquerade - Clanbook: Nosferatu
How often do you notice the servants?
— Image notes for The Maggot, Mage: The Sorcerer's Crusade - Infernalism
Video Games
"Children. The poor. My people's word for their kind is 'drala'fa': the ignored. They are everywhere, see everything, but are never seen."
— Thane Krios, Mass Effect 2
