Banksy
Born in 1974, Banksy (Robert or Robin Banks) is considered an "art terrorist" and chooses to remain anonymous by hiding his profile information and real name.
Working mainly in London, he stencils his art on city walls and buildings, leaving political messages, mainly against capitalism and authority. His common technique is to play on the perspective of the item on which he is stencilling.
In 2005 he exhibited his work without permission at the MoMA and the TATE Britain.