Demonstrators held a protest against internet censorship in Russia's second city of St. Petersburg on Sunday, local police said.
The event passed off peacefully "with no infringements of the law," the police said.
The Russian government is currently considering a law "On protection of children from information causing harm to health and development," limiting publication of a range of information in the media.
Content would be classified for different age bands such as "6+," "12+," "16+" and "18+". The "18+" category relates to information such as that which is dangerous to life or promotes suicide, could lead to illegal conduct, promote drug, alcohol or tobacco use, prostitution, hooliganism, taking part in reckless games, questioning family values and respect for parents, or containing pornography.