Opposition figurehead Alexei Navalny cheered by supporters after spending 15 days in police custody over protests.
Russia is gearing up for more protests in the wake of December’s controversial elections as demonstrators turn to newer forms of technology to try to prevent Putin’s re-election in March’s presidential poll.
The country’s opposition rallies have grown rapidly, much like those in the Arab world, in large part due to the power of internet.
Social-networking sites have become an important tool in raising money and support for anti-Kremlin causes.
Al Jazeera’s Neave Barker reports from Moscow.