Ai Weiwei, the artist behind the 2008 Olympics' famous Bird's Nest stadium (and last year's Tate Modern Turbine Hall show), has been detained by Chinese authorities in Beijing after attempting to board a flight to Hong Kong. Ai—a funny guy whose "Study in Perspective" series has a special place in our eternally-teenaged hearts—has been "keeping an informal tally" on Twitter of the writers and activists detained by China in its latest series of crackdowns; as of this writing it's unclear whether he'd been "formally detained" (bad news) or simply held for questioning (less bad news). Police have also surrounded his Beijing studio and cut off its power, just in case any art escapes. [WSJ; image via MoMA ("Study in Perspective - Beijing") and AP]