In a lengthy article published online last fall, three Russian rights activists argued that a strident, vulgar and uniform pro-Kremlin ideology had so permeated blogs and chat rooms that it could only be the result of a coordinated campaign.

Putin's allies in the online world acknowledge that the Internet represents a challenge to the status quo in Russia, which has, since Soviet times, relied on state-controlled television to influence public opinion across the country's 11 time zones.

Allies of the Kremlin have also begun buying some of the companies that have helped make the Internet a bastion of free expression in Russia. Gazeta.ru, long the country's most respected online newspaper, was sold in December to a metals magnate and Putin loyalist.

And last October, Sup, which is owned by Alexander Mamut, a tycoon with ties to the Kremlin, bought the rights to develop the Russian-language segment of U.S.-based LiveJournal. The segment, with half a million users, is Russia's most popular blog portal.

"Mr. Rykov is pro-Kremlin. Mamut and Sup are pro-Kremlin. The social networks are all being bought by pro-Kremlin people," Ruslan Paushu, 30, a popular blogger who works for Rykov, said in an interview. "Everything's okay."

Wolfgang Kleinwaechter, special adviser to the chairmen of the Internet Governance Forum, a group convened by the United Nations, said some Russian officials he has spoken to are considering a separate Internet, with Cyrillic domain names, and appear to be studying China's Internet controls.