In a move that could have major implications for social networking sites like Twitter and Facebook, Russian President Vladimir Putin signed a law Tuesday strengthening regulations on Internet data storage.

Starting in 2016, the new law will require Internet operators to store Russian user data in centers within the country. Once data is stored on Russian servers, it will be subjected to Russian laws, putting it at risk for censorship, critics say. Companies that don't comply will be blocked from the web.

The law is part of a plan to improve "the management of personal data of Russian citizens on computer networks,” Agence France-Presse reported. Critics say it could have a chilling effect on a variety of websites, including Facebook and Twitter, which do not have Russian data centers.

"Analysts say the new law will isolate Russians as foreign websites — including hotel and airline booking sites — will be required either to store users' data in Russia, or cease operations in the country," The Moscow Times reported.

The new law came as part of a "flurry of new legislation" on Tuesday, including a law prohibiting protests. Some of the Internet operators targeted have warned that two years is not enough time to comply with the law, according to the Agence France-Presse report.

The data storage law is the most recent in a history of Russian laws criticized for fostering censorship. Another recent law requires blogs with an audience of more than 3,000 daily views must register as media and be subjected to monitoring.

"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," Internet expert and blogger Anton Nossik told the Moscow Times of the data storage law.