researchers found that in the wake of the arrest of Telegram founder Pavel Durov and charges against leaders of the so-called Terrorgram Collective, dozens of extremist groups have moved to the app SimpleX Chat in recent weeks over fears that Telegram’s privacy policies expose them to being arrested.”
Why are they moving from telegram?
Telegram has been supplying US government with data on its users
https://www.404media.co/telegram-confirms-it-gave-u-s-user-data-to-the-cops/