The country's communications regulators have required Facebook, Twitter and YouTube to remove material the officials determined was objectionable, with only YouTube, owned by Google, resisting. The video-sharing site complied with a Russian agency's order to block a video that officials said promoted suicide. But YouTube filed a lawsuit in Russian court in February saying the video, showing how to make a fake wound with makeup materials and a razor blade, was intended for entertainment and should not be restricted.
Supporters of the law, which took effect in November, say it is a narrowly focused way of controlling child pornography and content that promotes drug use and suicide.
But opposition leaders have railed against the law as a crack in the doorway to broader Internet censorship. They say they worry that social networks, which have been used to arrange protests against President Vladimir V. Putin, will be stifled.
The child protection law, they say, builds a system for government officials to demand that companies selectively block individual postings, so that contentious material can be removed without resorting to a countrywide ban on, for example, Facebook or YouTube, which would reflect poorly on Russia's image abroad and anger Internet users at home.
So far at least, the Russians have been mostly singling out not political content but genuinely distressing material posted by Russian-speaking users.
On Friday, Facebook took down a page globally that was connected to suicide after it was flagged by the Russian regulatory agency, called the Federal Service for Supervision in Telecommunications, Information Technology and Mass Communications, known by its acronym Roskomnadzor. A spokesman for the agency had told Facebook it had until Sunday to comply or risk being blocked in Russia.
For Facebook, the response turned out to be an easy decision. Everybody concerned - the company, the government and opposition figures agreed the suicide-themed user group was not a friendly page. The group, called "Club Suicid," was deemed serious enough not to be sheltered by Facebook's criteria for "controversial humor."
Facebook says it also complies with local legislation to ban content in certain countries, though that was not the reason for removing the page in this case.
"Notable examples of where most services, including ours, will I.P.-restrict access for certain counties are in Germany" and in France, where it blocks content related to Holocaust denial, and in Turkey, where content defaming the country's founder, Mustafa Kemal Ataturk, is blocked, Facebook said in its statement.
The spokesman for the Roskomnadzor agency, Vladimir Pikov, said a separate government agency, Rospotrebnadzor, a consumer-protection organization intended to ensure the safety of food and consumer goods, had made a determination that the Facebook post promoted suicide, and was thus a public health threat.
Twitter, the microblogging site, in March began complying with Russian requests to remove posts - two because they appeared to be related to an attempt to deal in illegal drugs and three posts for "promoting suicidal thoughts," according to a statement issued March 15 by Roskomnadzor. Twitter has been "actively engaged in cooperation," the statement said.
Izvestia, a Russian newspaper, reported that Twitter and the Russian agencies' officials had been in negotiations since November to create a mechanism for selectively blocking Twitter posts inside Russia.
Anton Nosik, a blogger and journalist in Russia, in a telephone interview called the law "absurd, harmful and absolutely unnecessary." But, he said, so long as regulators focus on genuinely macabre material like sites visited by people fascinated by suicide, he is not overly concerned about a crackdown on the videos and Web pages in the Russian blogosphere. "The track record of the authorities shows they are not going to enforce it strictly."
© 2013, The New York Times News Service