When a group of friends choose someone on their friends list and deface their wall with photos of penises, things that look like penises, and things generally penis-related, so that the only things present when someone visits is things involving penises.
Can be used as a verb or noun.
Aw man, I left Facebook for an hour and you guys totally gave me a dick wall. You're a bunch of jerks.
Holy crap! I got dick walled by Carey, Kym, Matt, Dave, and Jen while I was asleep! I guess I should make my profile friends-only now, in case this happens again. Don't want the boss to see it by accident.