Telegram gave more user data to French authorities after founder's arrest
Pavel Durov, the founder and chief executive officer of the messaging app, was arrested in Paris last August over criminal content posted by users on his platform

https://www.lemonde.fr/en/pixels/article/2025/01/08/telegram-gave-more-user-data-to-fre...

Wenn Du was ohne Behoerden willst.

Matrix
https://de.wikipedia.org/wiki/Matrix_(Kommunikationsprotokoll)

Oder warum nicht das Original? WhatsApp basiert ehemals auf Jabber.

https://mtmedia.org/manuals/jabber-otr/

Neben Pidgin ist Dino eine Implementierung: https://dino.im/

Weitere Alternative waere noch Signal: https://dino.im/