signal app
The Russian internet watchdog Roskomnadzor has restricted access to the messaging app Signal, citing legal issues.

Signal has long been promoted as a secure messenger, but critics have warned that it was developed and kept afloat with US intelligence funding.

In a statement to the media on Friday, Roskomnadzor said the ban was "due to the violation of requirements of Russian legislation, the implementation of which is necessary to prevent the use of the messenger for terrorist and extremist purposes."

The statement came several hours after Russian users of the app began complaining about outages.

Signal was once recommended by NSA whistleblower Edward Snowden and tech mogul Elon Musk as a way to exchange messages away from the prying eyes of intelligence agencies. However, concerns about the application go back almost as far.

The Open Technology Fund that provided seed money for Signal's developer in the early 2010s was a cutout of the US State Department, under then-Secretary of State Hillary Clinton's 'Internet Freedom' initiative. According to the New York Times, Washington had sought to create "'shadow' internet and mobile phone systems dissidents can use to undermine repressive governments" through color revolutions, for example.

In 2017, WikiLeaks revealed that Signal's encryptions could be easily bypassed by the CIA, using the hacking tools described in the Vault7 disclosures. In January 2022, the Swiss army banned the use of Signal, WhatsApp and Telegram, citing data protection concerns.

The US government funding for Signal reportedly ran dry last December, and the app began to struggle. Musk, who had endorsed the app in 2021, warned about "known vulnerabilities" that were "not being addressed" in May.

Russian authorities have sought to crack down on a variety of Western internet platforms in recent years, usually citing data privacy concerns as well as their hostile policies and censorship in connection with the Ukraine conflict.