A Russian opposition activist holds an poster depicting Russian Prime Minister Vladimir Putin during a protest against vote rigging in St. Petersburg, Russia, Monday, March 5, 2012. More then 100 protesters were arrested in St. Petersburg, where some 2,000 gathered for an unauthorized rally to protest Russian Prime Minister Vladimir Putin's victory in Russian presidential election. (AP Photo/Dmitry Lovetsky)

A Russian police officer detains an opposition activist as his friends try to free him during a protest against alleged vote rigging in St. Petersburg, Russia, Monday, March 5, 2012. More then 100 protesters were arrested in St. Petersburg, where some 2,000 gathered for an unauthorized rally to protest Russian Prime Minister Vladimir Putin's victory in Russian presidential election. (AP Photo/Dmitry Lovetsky)

Russian police officers detain an opposition activist during a protest against alleged vote rigging in St. Petersburg, Russia, Monday, March 5, 2012. More then 100 protesters were arrested in St. Petersburg, where some 2,000 gathered for an unauthorized rally to protest Russian Prime Minister Vladimir Putin's victory in the presidential election. (AP Photo/Dmitry Lovetsky)

Riot police officers block opposition activists during a protest against vote rigging in St. Petersburg, Russia, Monday, March 5, 2012, with the St. Isaak's Cathedral seen in the background. More then 100 protesters were arrested in St. Petersburg, where about 2,000 gathered for an unauthorized rally to protest Prime Minister Vladimir Putin's victory in Russian presidential election. (AP Photo/Dmitry Lovetsky)

Russian riot police officers block opposition activists during a protest against alleged vote rigging in St. Petersburg, Russia, Monday, March 5, 2012. Demonstrators contested the outcome of the Russian presidential election Monday, pointing to a campaign heavily slanted in Russian Prime Minister Vladimir Putin's favor and to reports of widespread violations in Sunday's ballot. (AP Photo/Dmitry Lovetsky)

Police officers detain an opposition activists during a protest against vote rigging in St. Petersburg, Russia, Monday, March 5, 2012. More then 100 protesters were arrested in St. Petersburg, where about 2,000 gathered for an unauthorized rally to protest Prime Minister Vladimir Putin's victory in Russian presidential election. (AP Photo/Dmitry Lovetsky)

Police officers detain an opposition activists during a protest against vote rigging in St. Petersburg, Russia, Monday, March 5, 2012. More then 100 protesters were arrested in St. Petersburg, where about 2,000 gathered for an unauthorized rally to protest Prime Minister Vladimir Putin's victory in Russian presidential election. (AP Photo/Dmitry Lovetsky)

Police officers detain an opposition activist during a protest against vote rigging in St. Petersburg, Russia, Monday, March 5, 2012. More then 100 protesters were arrested in St. Petersburg, where about 2,000 gathered for an unauthorized rally to protest Prime Minister Vladimir Putin's victory in Russian presidential election. (AP Photo/Dmitry Lovetsky)

Police officers detain opposition activists during a protest against vote rigging in St. Petersburg, Russia, Monday, March 5, 2012. More then 100 protesters were arrested in St. Petersburg, where about 2,000 gathered for an unauthorized rally to protest Prime Minister Vladimir Putin's victory in Russian presidential election. (AP Photo/Dmitry Lovetsky)

Russian police officers detain an opposition protester during a protest near the Central Election Committee in Moscow, Monday, March, 5, 2012. Demonstrators are contesting the outcome of Russia's presidential election, pointing to a campaign heavily slanted in Putin's favor and to reports of widespread violations in Sunday's ballot. (AP Photo/Sergey Ponomarev)

Russian police officers detain opposition leader Edouard Limonov during a protest near the Central Election Committee in Moscow, Monday, March, 5, 2012. Demonstrators are contesting the outcome of Russia's presidential election, pointing to a campaign heavily slanted in Putin's favor and to reports of widespread violations in Sunday's ballot. (AP Photo/Sergey Ponomarev)

Russian police officers detain an opposition protester during a protest near the Central Election Committee in Moscow, Monday, March, 5, 2012. Demonstrators are contesting the outcome of Russia's presidential election, pointing to a campaign heavily slanted in Putin's favor and to reports of widespread violations in Sunday's ballot. (AP Photo/Sergey Ponomarev)

Russian police officers detain an opposition protester during a protest near the Central Election Committee in Moscow, Monday, March, 5, 2012. Demonstrators are contesting the outcome of Russia's presidential election, pointing to a campaign heavily slanted in Putin's favor and to reports of widespread violations in Sunday's ballot. (AP Photo/Sergey Ponomarev)

Russian riot police close in on hundreds of opposition activists who refused to leave the venue after a mass rally against Vladimir Putin's victory in presidential polls at Moscow's Pushkin square on March 5, 2012. Strongman Vladimir Putin reclaimed the Kremlin in a crushing presidential election victory that he declared was honest but the opposition said was undermined by serial violations. AFP PHOTO / JOHN MACDOUGALL

Russian riot police close in on hundreds of opposition activists who refused to leave the venue after a mass rally against Vladimir Putin's victory in presidential polls at Moscow's Pushkin square on March 5, 2012. Strongman Vladimir Putin reclaimed the Kremlin in a crushing presidential election victory that he declared was honest but the opposition said was undermined by serial violations. AFP PHOTO / JOHN MACDOUGALL

Police officers block opposition demonstrators after the massive rally in Pushkin Square protest in Moscow, Russia, Monday, March 5, 2012. Riot police on Monday broke up an opposition protest contesting Prime Minister Vladimir Putin's victory in Russia's presidential election, arresting dozens of participants, including prominent opposition leaders. (AP Photo/Alexander Zemlianichenko)

Russian police officers detain a protester after a rally in Moscow, Russia, Monday, March 5, 2012. Riot police on Monday broke up an opposition protest contesting Prime Minister Vladimir Putin's victory in Russia's presidential election, arresting dozens of participants, including prominent opposition leaders. The police action followed a rally in Moscow that drew about 20,000 protesters angry over a campaign slanted in Putin's favor and reports of widespread violations in Sunday's ballot. (AP Photo/Mikhail Metzel)

Protest leader Alexei Navalny speaks during a rally in Moscow, Russia, Monday, March 5, 2012. Riot police on Monday broke up an opposition protest contesting Prime Minister Vladimir Putin's victory in Russia's presidential election, arresting dozens of participants, including prominent opposition leaders. The police action followed a rally in downtown Moscow that drew about 20,000 protesters angry over a campaign slanted in Putin's favor and reports of widespread violations in Sunday's ballot. (AP Photo/Misha Japaridze)

Russian police officers detain a protester after a rally in Moscow, Russia, Monday, March 5, 2012. Riot police on Monday broke up an opposition protest contesting Prime Minister Vladimir Putin's victory in Russia's presidential election, arresting dozens of participants, including prominent opposition leaders. The police action followed a rally in downtown Moscow that drew about 20,000 protesters angry over a campaign slanted in Putin's favor and reports of widespread violations in Sunday's ballot. (AP Photo/Mikhail Metzel)

Russian police officers detain a protester after a rally in Moscow, Russia, Monday, March 5, 2012. Riot police on Monday broke up an opposition protest contesting Prime Minister Vladimir Putin's victory in Russia's presidential election, arresting dozens of participants, including prominent opposition leaders. The police action followed a rally in Moscow that drew about 20,000 protesters angry over a campaign slanted in Putin's favor and reports of widespread violations in Sunday's ballot. (AP Photo/Mikhail Metzel)