LONDON, UNITED KINGDOM - SEPTEMBER 15: Ai Weiwei stands with his sculpture 'Straight' as he previews works from His landmark art exhibition on September 15, 2015 in London, England. The Royal Academy of Art is showing the work of one of China's leading contemporary artists until mid-December. Ai Weiwei's activism in China saw him detained without charge in 2011 for 81 days. (Photo by Alex B. Huckle/Getty Images)
