Despite Telegram's origins, its approach to users' security has privacy advocates worried. Perpetrators of such fraud use various marketing techniques to attract subscribers on their social media channels. Groups are also not fully encrypted, end-to-end. This includes private groups. Private groups cannot be seen by other Telegram users, but Telegram itself can see the groups and all of the communications that you have in them. All of the same risks and warnings about channels can be applied to groups. The gold standard of encryption, known as end-to-end encryption, where only the sender and person who receives the message are able to see it, is available on Telegram only when the Secret Chat function is enabled. Voice and video calls are also completely encrypted. Just days after Russia invaded Ukraine, Durov wrote that Telegram was "increasingly becoming a source of unverified information," and he worried about the app being used to "incite ethnic hatred."
from ru