Earlier this week we told you that Chinese artist Ai Weiwei had gone “missing” after being taken into police custody. Now, led by the efforts of the Guggenheim, some of the world’s most respected museums — including the Museum of Modern Art, the Los Angeles County Museum of Art, the Minneapolis Institute of Arts, and the Tate Modern — are circulating an online petition directed at the Minister of Culture of the People’s Republic of China, Cai Wu, for his immediate release. The Tate Modern — where Ai’s Sunflowers is on display in the Turbine Hall through May 12th — gets bonus points for taking the IRL approach too. [Image via @robbiesharp]