Russia has filed protocols against Facebook and Google for what Roskomnadzor, the country's communications regulator, says is the social-media networks' failure to remove banned content.
The official TASS news agency on May 5 quoted a court source as saying five protocols against both Google and Facebook were received by the court, with potential fines amounting to 200 million rubles ($267,000) each.
Another social-media giant, Twitter, has already been handed protocols for similar violations, which could see it fined as much as $320,000, the source added.
The moves are the latest in a major dispute Moscow has with global social-media platforms over content allegedly related to political protests.
Russian critics of the Kremlin routinely use international social networks to get around state control of the media and reach tens of millions of citizens with their anti-government messages.
Imprisoned Kremlin critic Aleksei Navalny in January used U.S. social-media networks to organize some of the largest anti-government protests since 2011-12.
Russian authorities have gone as far as to threaten to ban social media. Even though they have recently backed away from such threats, Russian regulators have punitively slowed user connections.
No date for the hearing has been set, TASS said. Roskomnadzor, Twitter, and the court did not immediately respond to requests for comment.