Claiming that it had received multiple bomb threats via email messages, the Russian government restricted internet access, which resulting in blocking ProtonMail email servers, according to PortSwigger.
In a March 12 blog post authored by Andy Yen, ProtonMail founder, Yen called the block "unjustified" and promised to restore full service to users in Russia. “The Russian government has ordered a partial block of ProtonMail, preventing some Russian mail servers from reaching us. We have managed to restore services at this time,” ProtonMail tweeted.
According to Yen, the Federal Security Service of the Russian Federation (FSB) issued a letter on February 25 in which the FSB issued a block on two internet service providers in the aftermath of what it called fake terror threats. The blocks on MTS and Rostelecom prevented traffic from Russia going to ProtonMail’s mail servers, which effectively blocked communication with ProtonMail.
“However, the method of the block (preventing messages from being sent to ProtonMail, as opposed to blocking delivery of messages from ProtonMail) seems inconsistent with that claim. Due to the timing of the block, some ProtonMail users in Russia suspect that the block may be related to the mass protests this past weekend in Russia where 15,000 people took to the streets to protest for more online freedom."
The block came after thousands of protesters in Russia flocked to the streets on March 10 to express their outrage at a cybersecurity bill that tightened restrictions on the internet, according to the BBC.
“If there is indeed a legitimate legal complaint, we encourage the Russian government to reconsider their position and solve problems by following established international law and legal procedures, rather than attempting to deny millions of Russian citizens access to better email security and privacy,” Yen said.
The Russian government recently passed additional legislation restricting using the internet to speak out against the government or to spread of "fake news."