Early today, Roskomnadzor—Russia's Federal Service for Supervision of Communications, Information Technology and Mass Media—moved to enforce a new Russian federal law blocking the use of Telegram, the encrypted chat and social networking application that has become the favored tool of Russia's political opposition and journalists. The censorship began with Roskomnadzor instructing Internet service providers to block requests to Internet Protocol addresses of Telegram's servers.

But as users flocked to virtual private networks and proxy services to reach Telegram from their mobile devices and computers—or resorted to building their own—government censors added large swaths of IP addresses to the block list. And according to multiple sources within Russia, ISPs there are now blocking large chunks of IP addresses associated with cloud services from Amazon and Google.

Alexander Zharov, the chief of Roskomnadzor, confirmed that Amazon's addresses were being blocked "due to the fact that the Telegram messenger started using them to bypass the lock in Russia," RT reported.

Telegram isn't the first secure chat application targeted by the Russian government. The chat application Zello is also widely blocked in Russia. More than 800,000 Amazon IP addresses were being blocked by early evening in Moscow, and a block of more than 1 million Google addresses (35.192.0.0/12) was added shortly afterward, according to a report from the Meduza Project.

These addresses are added atop hundreds of thousands of addresses already blocked, many of them targeted to stop Zello users from bypassing censorship. According to Meduza, Amazon asked Zello to stop using its servers to get around the ban, forcing Zello to move its servers to Google's cloud service.

As of midnight Moscow time, more than 15 million IP addresses were being actively blocked by ISPs, based on tracking by a Russian hosting service provider posted on a domain registered to Russia's Foundation for Assistance for Internet Technologies and Infrastructure Development. The site also provides instructions for downloading proxy server images for use on cloud services.

Ars asked Amazon and Google for confirmation of the blocked traffic, but neither company has yet responded. Protests over the blocking of Telegram continue in Russia.