Russia plans to crack down on the fake news at home with a proposed law which critics say could limit freedom of speech on the internet. The bill, submitted by lawmakers from the governing party, United Russia, proposes holding social networks accountable for inaccurate comments posted by the users. Under existing Russian law, social media users can be punished for content deemed to promote homosexuality, threaten public order or be extremist in nature, with fines as well as imprisonment.

Under the proposed rule, part of a creeping crackdown on digital rights under President Vladimir V. Putin, websites with more than 100,000 daily visitors and a commenting feature must take down factually inaccurate posts or face a fine of up to 50 million rubles, about $800,000. The bill gives social media companies 24 hours to delete “inaccurate” information after being notified of its existence, raising concerns that moderators will be left to interpret the term, which is vaguely defined in the measure. The legislation has passed one of three votes in Parliament.

Critics worry that out of an abundance of caution, moderators are likely to interpret truthfulness to the authorities’ advantage. They say the bill would make it easier for the state to pressure social media companies to cooperate with security services by requiring them to establish offices in Russia, a step that the social media giants Facebook and Twitter have avoided so as not to fall under Russian legal jurisdiction. Internet companies, which have often borne the financial costs of restrictions in Russia, say that too many people write posts and leave comments for moderators to thoroughly review every potential instance of false news within 24 hours.

Vladimir V. Zykov, the head of an association of social media users in Russia, warned in a recent meeting with lawmakers that the bill will become an instrument of censorship unless social media companies develop algorithms to distinguish real news from fake news, removing the human element and potential bias.