https://www.techradar.com/news/as-telegram-ban-tightens-workaround-options-are-slim-for-russians

Russia has made it abundantly clear: If the government can’t see its citizens’ conversations, then they just can’t have them.

In mid-April, the country’s top spy agency FSB moved to block Telegram - a wildly popular messaging app that allows users to send encoded chats - after the company refused to hand over the keys that would allow the agency to decrypt the conversations.