Less than a month since it managed to reach 200 million users within a 30-day period, Telegram Messenger has to take a serious blow as the Russian authorities decide to ban its use in the country. The reason for this decision is the company's unwillingness to provide the keys required by the Federal Security Service to decrypt the users' messages.
https://www.notebookcheck.net/Russian-authorities-ban-Telegram.298888.0.html