I wrote:
Another one that seems worth mentioning, for secure messaging, is Telegram. One seeming point in its favour is that it has been recently banned in Putin’s Russia. But the service is so resilient that in trying to block it, they have ended up taking out Russian access to rather large parts of the entire Internet <https://www.techdirt.com/articles/20180417/13133139649/trying-to-ban-telegram-russia-breaks-internet.shtml>.
Further to the above <https://www.aljazeera.com/news/2018/04/internet-civil-war-erupted-russia-180423124936679.html>: According to Stanislav Shakirov, technical director of Roskomsvoboda (a wordplay on Roskomnadzor meaning RoskomFreedom), an anti-censorship NGO, Telegram has managed to weather the pressure because of its well-made architecture. "[Telegram architects] had set up a rotation of servers which the app links up to. This makes it difficult for Roskomnadzor to block it," Shakirov explained. ... Scrambling to block a massive number of IP addresses, which reached 20 million on April 19, Roskomnadzor ran up against another problem: the disruption of other services using the same IP address clusters as Telegram. Mid-week, reports started coming in of various companies experiencing difficulties with their online operations: from international companies such as Viber and taxi service Gett, to Russian ticket booking service Kupiblet and supermarket chains like Diksi.