v. The act of leaving ones facebook alone and unattended around drunk, creative young adults with nothing better to do than fuck with each other. The consequences can be devastating. Changed names, relationship statuses and your grandmas photos fro her trip to the bahamas are all free game. One can only untag, apologize, explain to your aunt why you "liked" anal sex and move on. Turn facebook into fun with Facemucked.
Shit i left my facebook open and i got FaceMucked!!!!!