@pixelcode @alshafei again: That is mitigateable by having plausible deniability of said identities and using @torproject / #Tor to connect to said services.
In fact, just using #Orbot and @monocles / #monoclesChat allows you to connect to any XMPP Service, including those that have an #OnionService.
It takes mere seconds to get someone setup and ready to go!
Whereas with #centralized, #proprietary & #SingleVendor / #SingleProvider services, your only security is said provider/vendor saying "#TrustMeBro!"...
Espechally tying accounts to #PhoneNumbers is a big no-go IMHO because that's trivial if not already being spied upon by LEAs and in more juristictions than ever before it's basically illegal to acquire any #SIM without "identification" aka. self-doxxing towards the provider!
And if you really need like an organization group chat, self-hosting #Zulip is an option, as the messages are kept on the server and you just kick user accounts if they get arrested or their equiment confiscated.
#ComSec & #InfoSec necessitate proper #OpSec & #ITsec anyway...