The agency allowed those websites to reopen after the "offensive content" was pruned. But experts say those examples were hugely popular websites whose closure attracted immediate public attention and a storm of complaints; restoring service may not prove so easy for smaller victims of the law.
"The first several days of operation of this law have confirmed our worst fears," says Oleg Kozyrev, a media analyst and popular blogger.
"Roskomnadzor can shut down a site within 24 hours, without appealing to a court. But in order to restore a resource, one has to complain and go to court. Even so, the rules for getting back online are not at all clear ... As a result, big resources like YouTube, or internet encyclopedias, or social networks are all under threat. They have millions of users, and some of them are inevitably going to post something deemed offensive. That could lead to the closure of the whole portal," which will be disruptive even if it's temporary, he says.
The head of Roskomnadzor, Alexander Zharov, told journalists this week that big Russian social networks are scrambling to cooperate with the agency, rather than face the possibility of being axed.
"The response from national social networking sites has been comprehensive and constructive, we have no problems with them," Mr. Zharov said.
That worries many opposition-minded Russians, who recall that the protest movement, which erupted last December over alleged electoral fraud was largely self-organized by citizens who communicated through social networks like Facebook and the Russian-language VKontakte.
"The criteria of this law are too vague, and the way we've seen it applied already gives us no grounds for optimism," says Sergei Davidis, a lawyer and member of the Solidarnost opposition group.