Why would someone accept your friend request on facebook then remove you later?

[Thanatos]

so basically i added someone in one of my classes back then from highschool she was super nice but then she removed me and this happened with a few other people as well i understand i didnt know these people very well but you cant tell me they are good friend and know half there friends there friends list? so why would someone do this?

[A]

Maybe they thought you weren't who you said you were. That's happened to me a couple times. Especially if you changed your fb name or something.

[anon]

maybe she just didnt want to be your friend on facebook anymore. she only wanted her close friends or family. or she either deactivated her account.