Ai Weiwei On Alcatraz Exhibit Focuses On Human Rights

SAN FRANCISCO, CA - SEPTEMBER 24: Visitors look at postcards that can be filled out and sent to prisoners during the @Large: Ai Weiwei on Alcatraz exhibition on September 24, 2014 in San Francisco, California. The new @Large: Ai Weiwei on Alcatraz will open to the public on September 27th and features a series of seven site-specific installations by artist Ai Weiwei in four locations on Alcatraz Island. The exhibition explores human rights and freedom of expression through large-scale sculpture, sound, and mixed-media works. The show runs through April 2015. (Photo by Justin Sullivan/Getty Images)