BERLIN, GERMANY - APRIL 02: The jade work "Handcuffs" lies on display during the press preview to the "Evidence" exhibition by Chinese artist Ai Weiwei at Martin Gropius Bau on April 2, 2014 in Berlin, Germany. "Evidence," which is among the biggest exhibitions of Ai Weiwei's work, will be open to the public from April 3 to July 7, 2014. (Photo by Sean Gallup/Getty Images)