The Fantastic Four also don't have secret identities, so people can just call their house and cellphones.
Because (1) it's not relevant to the "Bat Signal" discussion, (2) while the FF don't have secret identities, they DO live in a superhero headquarters, not a regular house, and while people can call their headquarters, it's just as easy to call the headquarters of the Avengers or Justice League despite them having secret identities (i.e., you don't look up "Richards, Reed" in the phone book to call the FF, you look up "Fantastic Four") and (3) the comic never suggests they have their cell phone numbers listed in the phone book, and since they're major (and very busy) celebrities, they almost certainly don't.
Removed from the Fantastic Four example:
Because (1) it's not relevant to the "Bat Signal" discussion, (2) while the FF don't have secret identities, they DO live in a superhero headquarters, not a regular house, and while people can call their headquarters, it's just as easy to call the headquarters of the Avengers or Justice League despite them having secret identities (i.e., you don't look up "Richards, Reed" in the phone book to call the FF, you look up "Fantastic Four") and (3) the comic never suggests they have their cell phone numbers listed in the phone book, and since they're major (and very busy) celebrities, they almost certainly don't.
Edited by LoserTakesAll