This is what we found on Wikipedia regarding the The Art of Banksy:

Banksy is a pseudonymous England-based street artist, political activist, and film director. He has never publicly confirmed his identity. Active since the 1990s, his satirical street art and subversive epigrams combine dark humour with graffiti executed in a distinctive stencilling technique. His works of political and social commentary have appeared on streets, walls, and bridges throughout the world. His work grew out of the Bristol underground scene, which involved collaborations between artists and musicians.

Banksy displays his art on publicly visible surfaces such as walls and self-built physical prop pieces. He no longer sells photographs or reproductions of his street graffiti, but his public "installations" are regularly resold, often even by removing the wall on which they were painted. Much of his work can be classified as temporary art. A small number of his works are officially, non-publicly, sold through an agency he created called Pest Control. Banksy directed and starred in the documentary film Exit Through the Gift Shop, which made its debut at the 2010 Sundance Film Festival. In January 2011, it was nominated for the Academy Award for Best Documentary Feature Film.