When someone attempts to belittle or humiliate a particular person or Facebook friend by updating his Facebook status. This person purposely avoids using the victim's name, but describes him or her in such a way that all mutual friends will immediately know who it is.
(in a status update)
John: wishes that all red-headed Poly-Sci majors who work at a certain law firm would stop facestalking me and get a life.
Mary: Did you see John's status update today?
Mark: Yeah, he was totally talking about Jenny! Who else do we know with red hair who works at a law firm?
Mary: I know, he so facesmacked her!
The art of trash talking not in person, but via a social networking site preferably facebook.
Steve: Jim was giving me all kinds of shit online yesterday because of what I posted on my facebook wall.
Tony: Don't let him bother you, he was just facesmacking.