I have spent a lot of time explaining to Russians and Ukrainians that Telegram is not a safe communications channel (I even wrote a Telegram Harm Reduction Guide) but people still use Telegram and they still tell me they do so because it's "safe" and "secure."
I hope that at the very least Telegram users in eastern Ukraine will stop.
https://www.pwnallthethings.com/p/russia-is-spying-on-telegram-chats