facebook games/apps ?

[Alexa]

so the other day i was playing a facebook game, and i added 28 neighbours on the game. once id got bored i went to my home page and got a friend request from a random i added on the game.
how did they know what my name was? or where to find me?
how do people do that? how can you find someone like that throu a game??
thank you very much
all 28 friends was added on the game not my fb page. i got one friend request from a random game player, no name or email was sent with the buddie request, thats why im confused