Associated Press
More than 10,000 people protest in St. Petersburg in December. A critical mass of young Russians decided this month that they had the power to alter the course of political events.

MOSCOW — On Friday afternoon, Denis Terekhov gathered together his employees for an impromptu staff meeting.

They were workaholics in their 20s, punchy from an apocalypse-themed office party. But Terekhov had another order of business. Watch yourself, he told them, if you choose to attend Saturday's anti-government protest.

A mystery has been unfolding here over the past month, and young Russians are in the middle of it. A critical mass of young Russians decided this month that they had the power to alter the course of political events. They organized outside the channels of mainstream politics and took the country's leadership by surprise.

No one can say how strong this burst of citizen activism will prove to be. But an impulse was released after December's parliamentary elections, which were widely discredited as fraudulent. It has rippled out through Russia's emerging middle class.

A look at the changes in one office, an Internet marketing and communications firm called Social Networks Agency, over the past month offers a glimpse into this mood.

One event that flipped a switch in this group was a simple mistake: On Dec. 5, police detained a project manager named Mikhail Kazakov.

Kazakov, 27, is so disgusted with the state of Russian politics that he swore off voting eight years ago. He happened to be leaving the glam Red Espresso Bar with a cup of coffee that night and found himself engulfed in a crowd that had gathered to protest election violations.

Kazakov explained that he was a pedestrian, but the police ordered him to set down his coffee on the sidewalk and pushed him onto a bus. He was charged with "actively resisting" the authorities.

The next day, the whole office was talking about it.

"There was some slight feeling of despair, because Misha was arrested for nothing," said Irina Lukyanovich, 23, a copy editor.

The night after Kazakov was detained, Lukyanovich left work and stood on the edge of a crowd that had gathered for the second time to protest violations in the parliamentary campaign. Most of the co-workers are keeping their distance, but they too, seem to be scanning the horizon for political alternatives. Kazakov, whose detention had infuriated his co-workers, remains resolutely skeptical of the whole movement.

A signal change has occurred already: Russia's opposition movement is the realm of the young. Planning meetings, once held in the musty domain of perestroika-era dissidents, are now convened at Moscow's most fashionable addresses.