Ai Weiwei, self-portrait, 2011
Ai Weiwei, Tompkins Square Park, New York, 1993
Ai Weiwei, self-portrait, Williamsburg, Brooklyn, 1983
Ai Weiwei, June 1994, Beijing, China
Ai Weiwei, self-portrait while taken in custody by the police, Sichuan, China, 2009
This episode of Frontline (full streaming video) is a good introduction to AI Weiwei and why he is being detained by the Chinese government.