Eisenberg said he quit after receiving a note from Facebook with suggestions about who he should befriend – after he’d joined with a fake name. He said:

One of them was a girl my sister was friends with in high school. I don’t know how they found her, no idea. I signed off right then.

Aaron Sorkin, Writer Of ‘The Social Network,’ Unfriends Facebook | TPM Idea Lab

Via: idealab.talkingpointsmemo.com.