Russian police detain an activist wearing a Vladimir Putin mask during an opposition protest in St. Petersburg December 8, 2011. Prime Minister Vladimir Putin accused the United States on Thursday of stirring up protests against his 12-year rule and said foreign countries were spending hundreds of millions of dollars to influence Russian elections. REUTERS/Alexander Demianchuk (RUSSIA - Tags: CIVIL UNREST CRIME LAW POLITICS TPX IMAGES OF THE DAY)