Twitter in Russia slowed to a crawl on February 26, two days after the invasion of Ukraine. By March 4, at about 08:00 UTC, the slowdown stopped on every network at once and turned into an outright block. That is the picture in measurement data collected by OONI, a project that tracks internet censorship, and published in a report dated March 7, 2022.
Facebook went dark the same day. OONI’s data shows facebook.com and twitter.com both blocked by March 4, mostly by a technique that injects a reset (RST) packet into the connection.
News sites and a site about war dead
The blocks reach well beyond social media. Russian providers have also begun cutting access to independent Russian outlets, among them Dozhd and New Times. Foreign broadcasters are on the list too: the BBC, Deutsche Welle, the Russian version of Voice of America and Radio Liberty’s Russian service.
One further target was 200rf.com, a site created by representatives of Ukraine’s Ministry of Internal Affairs to share information about captured and killed Russian soldiers.
Roskomnadzor, Russia’s media regulator, set the tone on February 24. Its statement said media organizations are obliged to “only use information and data received from official Russian sources.” It also warned that spreading knowingly false information carries an administrative fine of up to 5 million rubles, and that such material would be blocked immediately.
Not one wall but many
OONI stresses that none of this looks the same everywhere in Russia. Each internet service provider carries out government-ordered blocks on its own, so some networks block a site and others do not, and the methods differ. The most common, counting by providers, is the injection of an RST packet after the ClientHello message in the TLS handshake. Filtering at the DNS level is also widespread.
Even inside a single network the results can split. On some, OONI saw block pages served for a site while other tests from the same network, on the same day, found it reachable. Certain providers combine several techniques at once, which makes getting around the block harder.
The analysis rests on a subset of OONI Probe measurements from Russia and several European countries over the previous month. OONI Probe is run by volunteers, and volunteers in Russia have contributed 154,672,256 measurements from 2,600 local networks. The test used compares what a user’s connection returns for a site with what an uncensored control network returns, and flags differences as anomalies.
Russia was not alone in restricting content. After EU sanctions on Russian state-owned media, several European countries, including Greece and France, began blocking the websites of Russia Today and Sputnik News. Both Russia and the EU defend such measures as a way to limit misinformation.
Russian censorship was extensive before the invasion. OONI notes that Russia has blocked Ukrainian sites such as uapolitics.com, 24tv.ua and donbass.ua, along with numerous LGBTIQ websites and critical political sites including ej.ru, imrussia.org, kasparov.ru and fbk.info. Data suggests the website of opposition leader Alexei Navalny has been blocked since July 26, 2021.
