An individual who makes a ridiculous amount of statuses, always writes on everyone's wall, and overall just a news feed hog.
Mostly unnecessary wall posts, usually just for attention. The worst facebook foul's even wall post to people they have no real connection to.
Another component of a facebook foul is liking or commenting on things that the said person has nothing to do with. Wall posts for conversations are also a tell-tale sign of a chronic facebook foul.
Steve: "Dude, she just had 3 statuses, and 14 wall posts in 26 minutes.. :/"
John: "That's such a facebook foul"
Committing a foul against the social unwritten rules of Facebook.com, including immediate responses, message/wall chatting and most importantly, facebook stalking.
Z: Dude, that girl just commented on my status after only 45 seconds
N: That was a facebook foul. She's creeper status.