Discord have belatedly confirmed that they're working with Persona, an identity detection firm backed by a fund directed by Palantir chairman Peter Thiel.
Matrix because it seems like the most logical choice - largest platform that’s federated/decentralised and has end-to-end encryption.
Personally I’ve had consistent problems with messages not un-encrypting in Matrix, requiring frequent re-sending of messages. I’m also not a fan of how much Metadata is shared across the Matrix network even with encryption, nor am I fan of the history of the group (Amdocs) who developed and funded it, or the willingness of the Matrix/Element team to sell their services to law enforcement (They had purchased a booth at a police convention).
Movim has all of the same features as Matrix without those downsides, if you’d like to give that a try instead.
On selling services to law enforcement: I disagree. You would want your E2E encryption platform to be respected and recognized by law enforcement, so they don’t just think “oink oink, only criminals use this service, this guy must be a criminal!”
Personally I’ve had consistent problems with messages not un-encrypting in Matrix, requiring frequent re-sending of messages. I’m also not a fan of how much Metadata is shared across the Matrix network even with encryption, nor am I fan of the history of the group (Amdocs) who developed and funded it, or the willingness of the Matrix/Element team to sell their services to law enforcement (They had purchased a booth at a police convention).
Movim has all of the same features as Matrix without those downsides, if you’d like to give that a try instead.
On selling services to law enforcement: I disagree. You would want your E2E encryption platform to be respected and recognized by law enforcement, so they don’t just think “oink oink, only criminals use this service, this guy must be a criminal!”
I recommend this defcon talk if you haven’t watched it (I think its the right one, TOR developer talks about why he teaches federal agencies how to use TOR)