Hello,

Russia recently blocked access to one of our platforms, OONI Explorer: a large open dataset on internet censorship worldwide ( https://explorer.ooni.org/).

Today we published a *report, documenting the blocking of OONI Explorer in Russia* based on OONI data: https://ooni.org/post/2024-russia-blocked-ooni-explorer/

On 11th September 2024, we received an email from Roskomnadzor, informing us of their decision to block access to OONI Explorer. On the same day, OONI data shows that ISPs in Russia started implementing the block.

While Roskomnadzor mentioned their intention to restrict access to the Russian translation of our circumvention tool reachability measurements, in practice, the restriction is far-reaching. The block restricts access to all OONI data hosted on OONI Explorer.

On some networks in Russia, we are able to automatically confirm the blocking of OONI Explorer based on fingerprints. For example, OONI data shows that DNS resolution returns an IP that hosts a block page.

On most networks in Russia, access to OONI Explorer appears to be blocked by means of TLS interference. Many measurements resulted in timeout errors and connection reset errors right after the Client Hello message during the TLS handshake.

While ISPs in Russia blocked access to OONI Explorer, they did not block access to our main website (ooni.org), nor to our censorship measurement app (OONI Probe) – as suggested by the fact that the overall OONI measurement coverage from Russia seems quite stable.

It is still possible for people in Russia to download OONI data from the OONI API (https://api.ooni.io/) or to fetch OONI data from our S3 bucket ( https://docs.ooni.org/data/).

We thank OONI Probe users in Russia for contributing measurements!

~ OONI team.