To ambush a desired facebook friend with a friend request, taking would-be friend by surprise due to lack of real-world friendship. Synonymous with "ambook."
"Dude, that chick is so hot. I facebushed her so I could see all her pics and beat off to the good ones."
"Weird, that quiet kid in my French class facebushed me. He's totally creepy, but I guess I'll accept."
It's when someone loses it on Facebook and starts mocking the innane entries by their so-called "Facebook Friends".
Also, similar to "Suicide by Cop", it is when a Facebook participant doesn't want to simple commit Facebook Suicide themselves, but wants to piss off enough of their friends that they all de-friend them.
Kouts is going crazy, He's facebushing all his current friends and Christos X. just de-friended him!
Did you see Kouts diss Christos X. by facebushing his existence and his posts?