Putin sworn in as riot police clash with protesters
APTOPIX Russia Putin
Russian President Vladimir Putin, left back, and former President Dmitry Medvedev watch a parade of the Kremlin's honor guards in Cathedral Square after the inauguration ceremony at the Kremlin in Moscow on Monday, May 7, 2012. Vladimir Putin has been sworn in as Russia's president for a third term after four years as prime minister. (AP Photo/RIA Novosti Kremlin, Dmitry Astakhov, Presidential Press Service)