A woman takes a picture of protesters marching by during a demonstration in Moscow, June 12, 2012. Demonstrators gathered in a drenching rain in central Moscow on Tuesday, in a show of defiance toward a government that evidently hopes to bring an end to the large gatherings protesting Vladimir V. Putin that began here six months ago. (Dimitry Kostyukov/The New York Times)

DMITRY KOSTYUKOV, ASSOCIATED PRESS - NYT

Demonstrators with flags and placards fill the streets during a protest in Moscow, June 12, 2012. Demonstrators gathered in a drenching rain in central Moscow on Tuesday, in a show of defiance toward a government that evidently hopes to bring an end to the large gatherings protesting Vladimir V. Putin that began here six months ago. (Dimitry Kostyukov/The New York Times)

DMITRY KOSTYUKOV, ASSOCIATED PRESS - NYT

Opposition supporters listen to an orator during a massive rally in central in Moscow, Russia, Tuesday, June 12, 2012. Tens of thousands of Russians flooded Moscow's tree-lined boulevards Tuesday in the first massive protest against President Vladimir Putin's rule since his inauguration, as investigators sought to raise the heat on the opposition by summoning some of its leaders for questioning just an hour before the march.

Alexander Zemlianichenko, Associated Press - Ap

Demonstrators hold the flags of various groups during a massive protest against Putin's rule in Moscow, Tuesday, June 12, 2012. Thousands of Russians are gathering Tuesday for the first massive protest against President Vladimir Putin's rule since his inauguration as investigators summoned several key opposition figures for questioning in an apparent bid to disrupt the rally.

Mikhail Metzel, Associated Press - Ap