Vladimir Putin is renowned for photos of his shirtless escapades that are widely disseminated online and playfully described as "Putin porn," but the idea of pornography in Russia is not without controversy. In fact, the country's federal communications agency is gearing up to block 136 adult websites in the country following a court ruling that could effectively make internet porn illegal.

A district court in Russia's republic of Tatarstan has ordered the communications agency to add the porn sites to its blacklist of blocked web resources, which also includes political opposition sites and others that have run afoul of a contentious law passed last year punishing online extremism. Bizarrely, the court said it was responding to a complaint by the district prosecutor about protecting the rights of an unnamed group of people, according to a report published on Monday in the Russian daily Izvestia.

The court's decision argues that the sites "create a threat of violations to federal law, harm the development of an unnamed group of children, can cause them to want to engage in prostitution and impel them to commit acts of violence against people, propagandize nontraditional sexual relations and foster disrespect toward parents and other family members, controverting family values."

The district prosecutor reportedly found the 136 sites listed in his complaint by typing "prostitutes of Kazan" and "porno video" into Yandex.ru, Russia's most popular search engine. Under the court order, the sites will be blocked if they don't rid themselves of pornographic material within three days.

"This is the first time that a single decision by a court contains a requirement to restrict access to such a large number of pornography-orientated websites," Vadim Ampelonsky, a spokesman for the communications agency, told Izvestia. "Total traffic to these sites is in the millions of visits."

It's unlikely that many of them will comply. The list includes the American porn site xHamster.com, which the internet analytics company Alexa ranks as the 66th most popular site in world, as well as various Russian-based ones with names like "Pornosaurus" and "Sex Breakfast."

The court's ruling appears to be based on convoluted logic, arguing that international agreements signed by Russia take precedence over its domestic laws — though that was hardly the case when Russia annexed Crimea last year, breaking its promise in the 1994 Budapest Memorandum to "respect the independence and sovereignty and the existing borders of Ukraine."

It pointed to two international treaties from a century ago that ban the production, possession, and distribution of pornographic materials — the Agreement for the Repression of Obscene Publications, which the Russian Empire signed in Paris in 1910, and the subsequent Convention for the Suppression of the Circulation of, and Traffic in, Obscene Publications, which was signed by the Soviet Union in Geneva in 1923. The court determined that both still apply in Russia today.

The understanding is that the Russian Federation is the legal successor to the Soviet Union, and the agreements remain in force even though the federation didn't ratify them. At the same time, Article 242 of Russia's criminal code forbids the "illegal preparation and/or import" of pornographic materials, and fails to define what counts as legal distribution.

"On the one hand, there's nothing wrong with banning pornography sites," Sergei Pryanishnikov, an adult film director from St. Petersburg, told Izvestia. "But on the other hand, after the sale of pornography was legalized in several European countries, the number of sexual crimes decreased by more than five times."

Pornography is popular in Russia. Porn star Sasha Grey made national headlines when she visited the country to take part in an auto rally from Vladivostok to Moscow in 2013. Fans lined up to get her autograph and take photos with her in Sochi that May.

Grey made headlines again this year after pro-Russia propaganda claimed that she had been killed while volunteering as a nurse in eastern Ukraine.

Russia has also produced porn stars who have gone on to international fame, such as Alina Yeremenko, aka Alina Henessy, who in January won the Adult Video News Award for best sex scene in a foreign-shot production.

But with more than 80 million internet users and a growing enthusiasm for all things online, Russia's government has lately been cracking down on the web, beginning with a 2012 law allowing its federal communications agency to blacklist sites without a court order. Legislation passed last year creates a registry of popular bloggers and holds them subject to the same regulations as mass media, a move that has been criticized as a way to threaten opposition voices with criminal prosecution.

If the district court's ruling in Tatarstan has its intended effect, the country's smut enthusiasts will also soon feel the pinch.