The kind of stuff Banksy does is definately art, however "xxx wos 'ere", scrawled on a wall is graffiti, IMHO. There was a report in one of the newspapers recently about some of his work on the underground being painted over and also councils "destroying" it by painting it out. They said although they appreciated his talent, rules were rules and he was breaking them.... (or something to that effect). Shame really, the good stuff usually brings smiles to peoples faces and that's not easy to do in this day and age.