Unpunk
This list of Ashton Kutcher's Punk'd failures is more interesting than anything we've ever seen on his boring, punk-ass show. Ryan Phillipe, Michael Vartan and Edward Norton are amoung those who refused broadcasting rights on their already filmed segments. Black Eyed Peas, Lil Jon, Neve Campbell and others figured out they were being Punk'd while it was going on. More here.
And previously... Demi Moore's nipples get punk'd
