Rebellion can be an art form. And what's a more 'F You, I Won't Do What You Tell Me' art form than graffiti? It's not simply about 'sticking it to the man,' either – it is a legitimate kind of art. Some of the most famous contemporary artists also dabbled in graffiti and street art, from Keith Haring and Jean Michel-Basquiat to Shepard Fairey and Banksy.