Russian billionaire and presidential candidate Mikhail Prokhorov, center, gestures as he walks among demonstrators gathered for a massive protest against Prime Minister Vladimir Putin’s rule in Moscow, Saturday, Feb. 4, 2012. Thousands of Russians are taking to the streets of Moscow to demand an end to Prime Minister Vladimir Putin’s rule, challenging his bid to reclaim presidency in March. The protest expected to draw tens of thousands despite temperatures plunging to minus 20 degrees Celsius (minus 4 degrees Fahrengheit). (AP Photo/Sergey Ponomarev)