face rat
A person who spends all day assing around on Facebook looking for status updates in which they can post perverted or otherwise obscene comments on. Face rats also enjoy being tagging or being tagged by other face rats in pictures of things like: men with titties, women with fupas or penis or vagina shaped objects.
All of my friends are total face rats. We check our new notifications like a pervert checking his mail box for porno mags hoping someone has commented on the totally disgusting yet hilarious picture of the hairy guy with titties we posted.