Most often when a male encounters a female and gets the facebook add. The newly met female posts something flirty and is quickly met with a post right above by a girlfriend or the girlfriend's friend.
This is intended to let the male know that she read this new girl's post and does not approve of it.
NOTE: To prevent facebook cockblocks send private messages in the future.
Matt's facebook wall:
GF's post: Heyy babe, just wanted to say i love you so much! (translation: dont you fucking respond to that post below or i will rip off your nuts)
Shirley's post: hey matt, i had a great time last night with you! give me a call sometime :)
Matt: Yeah i met this hot chick last night at the concert, but lauren facebook cockblocked me when she wrote on my wall
The inability to post anything potentially objectionable or politically incorrect to your facebook account out of fear that your boss or co-worker may see it and exact retribution or blackmail.
"Man, I would like to post this article about why marijuana should be decriminalized, but I can't because my boss could see it and then, there goes my promotion". "Dude, you're facebook cockblocked, for real".