The act of using Facebook while intoxicated. May or may not include confessions of undying love to friends, ex's, or total strangers. Grammar and logic will likely be poor. Similar to a drunk dial.
Chris - "Dude, you left 11 incoherent wall posts on my profile last night. What the fuck?"
Spencer - "What? No, I didn't! Oh, wait...yeah, I was shitfacedbooking."
Chris - "You fuckass."
Facebooking while drunk. Kind of like drunk dialing, but lonelier.
"I did some shitfacedbooking last night and may have lost a few friends."