Russia's parliament has passed a law to force internet sites that store the personal data of Russian citizens to do so inside the country, a move the Kremlin says is for data protection but which critics see an attack on social networks.
The law, passed on Friday, will mean that from 2016, all internet companies will have to move Russian data onto servers based in Russia or face being blocked from the web. That would probably affect US-based social networks such as Facebook, analysts say.
Coming after new rules requiring blogs attracting more than 3,000 daily visits to register with a communications watchdog, and a regulation allowing websites to be shut without a court order, critics say the law is part of a wave of censorship.
"The aim of this law is to create [another] quasi-legal pretext to close Facebook, Twitter, YouTube and all other services," internet analyst and blogger Anton Nossik said. "The ultimate goal is to shut mouths, enforce censorship in the country and shape a situation where internet business would not be able to exist and function properly."
Russian President Vladimir Putin, an ex-KGB officer who has called the internet a "CIA project", denied that he was restricting web freedoms, saying his main concern was protecting children from indecent internet content.
Speaking to a business forum in May, he denied there were plans to ban Facebook and Twitter.
The Kremlin adopted a law earlier this year giving authorities power to block websites deemed either extremist or a threat to public order without a court ruling.