Some anonymous guerilla artist has been
hacking the heads off models in advertising posters in London. Dubbed the "East London Decapitator", he or she creates meticulously photoshopped overlays, with the figures' heads replaced with gory stumps and the surroundings splattered with blood, and pastes them over the advertisements. Nobody — not squeaky-clean Disney stars, not pop singers, not even computer-animated characters — is safe.
There is a Flickr photo set
here. It's pretty entertaining, as long as he/she doesn't escalate into beheading actual live models or something.
Comic on the Decapitator: http://www.wordsandpicturesonline.com/01-07-08.html