Occurs when one poor soul leaves a Facebook account open on a public computer, or any computer for that matter, and gets statuses, pictures, sexual orientation, friends, groups, videos, applications, and all other aspects fucked completely up.
Generally used to teach valuable lessons about locking your shit up.
*Matt has been Facebook Jacked.
Molly: Matt, how drunk were you last night?
Matt: Not very, why?
Molly: You Facebook status says you "got fucked in the ass super hard without lube and you liked it."
Matt: Damnit! They Facebook Jacked me again!!
Molly: Maybe you should learn to lock your shit up.