A Moscow court said on Monday (March 21) that Meta was guilty of "extremist activity", but the ruling will not affect its WhatsApp messenger service, focusing on the US firm's already-banned Facebook and Instagram social networks.
Meta did not respond to requests for comment after Moscow's Tverskoi District Court said in a press statement that it had upheld a lawsuit filed by state prosecutors on banning the company's activities on Russian territory.
Meta's lawyer Victoria Shakina had earlier told the court that the company was not carrying out extremist activities and was against Russophobia, the Interfax news agency reported.
It was not clear whether Meta would appeal the outlawing of the activities of Facebook and Instagram in Russia "on the grounds of realising extremist activity", a ban TASS cited judge Olga Solopova as saying would be enforced immediately.
Late on Monday, communications regulator Roskomnadzor said it will exclude Meta from the list of foreign entities operating on the Internet in Russia, and Instagram and Facebook from the register of social networks, according to news agencies.
Roskomnadzor also said that Russian media must label Meta and its social networks as prohibited when distributing information and are forbidden to display their logos.
Russia has in the past designated groups such as the Taliban and Islamic State as "extremist" but later expanded this to the Jehovah's Witnesses and jailed Kremlin critic Alexei Navalny's Anti-Corruption Foundation.
Facebook last year had 7.5 million users in Russia and WhatsApp had 67 million, researcher Insider Intelligence estimates, while Instagram has said its ban will affect 80 million users in Russia.
The implications of the ruling remain unclear as Facebook and Instagram are already banned in Russia and the court said WhatsApp would be unaffected by its ruling.
"The decision does not apply to the activities of Meta's messenger WhatsApp, due to its lack of functionality for the public dissemination of information," the court said.
Russia initially banned Facebook for restricting access to Russian media while Instagram was blocked earlier this month after Meta said it would allow social media users in Ukraine to post messages urging violence against Russian President Vladimir Putin and troops Moscow sent into Ukraine.
Russia calls the conflict a "special military operation" to disarm Ukraine and protect it from people it describes as dangerous nationalists.
Meta has since narrowed its guidance to prohibit calls for the death of a head of state and said its guidance should never be interpreted as condoning violence against Russians in general.
But the perceived threat to its citizens angered Russian authorities and led to the criminal case against Meta.
It was not immediately clear how the WhatsApp messaging service would be able to continue operating, since the court has put a stop to Meta's commercial activities.
Analysis of mobile internet traffic on Monday showed that Telegram, popular in Russia for a long time, has overtaken WhatsApp to become the country's most used messaging tool in recent weeks.
The prosecution sought to allay fears that people who find ways around bans on Meta's services may face criminal charges.
"Individuals will not be prosecuted simply for using Meta's services," TASS cited the prosecutor as saying in court.
But human rights lawyer Pavel Chikov said neither the court nor the prosecutor could guarantee the safety of Facebook or Instagram users, warning that any public displays of Meta symbols - on websites, shop entrances, on business cards - could be grounds for administrative charges and up to 15 days in jail.
"Buying adverts on both social networks or trading Meta's shares may qualify as financing extremism activity - this is a criminal offence," he wrote on Telegram.
WhatsApp may have been left alone due to the extent of its everyday use among Russians and by government agencies and state companies for customer support, Sarkis Darbinyan, head of the legal department at digital rights group Roskomsvoboda, said.
Another reason is likely to be to avoid any backlash.
"The government is trying not to close everything at once, but gradually, so that people slowly get used to it," he told Reuters, pointing to the "unpopular" closure of Instagram.
"We assume that services like WhatsApp could come under blocks at any moment," Darbinyan added.
Way back for Meta?
Russia's military operation in Ukraine has added fuel to a simmering dispute between foreign digital platforms and Moscow.
Access to Twitter has also been restricted and on Friday Roskomnadzor demanded that Alphabet Inc's Google stop spreading what it called threats against Russian citizens on YouTube.
Anton Gorelkin, a member of Russia's State Duma committee on information and communications who has criticised foreign firms, while championing domestic alternatives, said the Russian market could be opened to Meta again, but only on Moscow's terms.
"These are an immediate end to blocking Russian media, a return to the policy of neutrality, and strict moderation of fakes and anti-Russian comments," Gorelkin said on Telegram.
Another condition, Gorelkin said, was that Meta comply with a law requiring foreign firms with more than 500,000 daily users to open representative offices in Russia.