The practice of two or more facebook friends carrying on a conversation on the wall of a third mutual friend who does not use or otherwise check her facebook account very often. Facesquatting is especially effective after 9pm when wall postings are unmonitored by many users, especially those with kids or day jobs.
Dude let's facesquat on joey's wall - he's away and will have no idea for at least a week that we've had this conversation about his new girlfriend on his own wall!
To snatch up a Facebook "vanity url", the custom screenname now available on the popular social networking site.
Mike Pence facesquatted Obie Fernandez's name as his URL. It ruined their friendship.