Why it matters: We’re used to hearing about Facebook and Twitter going after Russian accounts that spread misinformation, but now it’s Russia’s turn to accuse the platforms of breaking the rules.

Roskomnadzor, the country’s state communications regulator, says it has begun “administrative proceedings” against the two social network platforms for their failure to store Russian users’ information within its borders—a law that came into effect back in 2015.

Roskomnadzor claims it sent Facebook and Twitter letters on December 17th advising them they had 30 days to offer a “legally valid response,” but neither provided one.

In a statement reported by the Wall Street Journal, Roskomnadzor said the companies “…hadn't submitted any formal and specific plans or submitted an acceptable explanation of when they would meet the country's requirements that all servers used to store Russians' personal data be located in Russia.”

Exactly what consequences Facebook and Twitter face is unclear. Fines seem likely, but even if the companies pay them, not implementing changes could result in more serious actions, including Chinese-style outright bans in Russia.

In November, Reuters’ sources said Moscow planned larger fines for technology firms that fail to comply with Russian laws.

Last year, Roskomnadzor and encrypted messaging platform Telegram were involved in a long-running battle over the app’s owners’ refusal to share its encryption keys with government agencies. It led to a court ordering Telegram to be blocked in the country, its removal from local app stores, and the banning of 50 VPNs and proxy servers. Russia also blocked more than 15.8 million IP addresses, which hampered other services such as game servers, banking, retail, and cryptocurrency websites.