They were pretty much under pressure by the Russian Government last time I looked, and didn’t so much as blink. Which is rather odd. Because staring is weird.
On a serious note, telegram is rather popular with a lot of people in Europe, and recently contacts pop up in my list which I never even dreamed about using something else than WhatsApp. However, most people don’t even KNOW that there’s an option for chats which are not stored on telegram’s servers, the so-called secret chats. Also, tying your account to a phone number is something that pisses me off.
FTR, same is true for other messengers like Signal, which I like very much, especially on Android since it also replaces the Messages App and encrypts the local messagebase, making it easier to keep other services’ accounts safe’ish when these are sending you unlock codes via SMS.
Since I’ve been working in Switzerland and Germany for a while, my threema contact list is also quite ok. Works without tying to a mobile number, message server is Swiss, but is closed source.