Ai Weiwei is arguably the most internationally celebrated Chinese artist of the modern era. The inscrutable bearded visionary burst onto the scene with vast conceptual installations such as his eight million hand-painted ceramic sunflower seeds inside Tate Modern and went on to design the iconic Bird's Nest stadium for the Beijing Olympics. But at heart, Ai Weiwei is a troublemaker with a serious agenda: to challenge the oppression of the Chinese people by their government with rebellious and irreverent gestures. His activism has cost him his freedom repeatedly, but he never seems to lose his childlike approach to serious dissidence executed with a wink.