This is an intriguing thing. An anti-establishment, art 'terrorist', who actually needs the establishment ... otherwise what would he rebel against?
Banksy is a grafitti artist from Bristol, UK, who's work is popular, but not neccessarily populist - his choices of subject are too challenging for that: the Western world's reaction (or lack of) to AIDS in Africa, the 'security wall' between Israel and Palestine, inner-city deprevation in London.
The BBC have a brief article about him, but it was actually Alec Muffett who first brought Banksy to my attention some time ago (before the blog post linked above).
Of course, not everybody likes him. Paris Hilton and the Tate Museum of Modern Art (more comments on that subject another time!) have both 'suffered' from Banksy's not-so tender mercies.