It's very clear on signup, on the READMEs, even on the DM portal itself, that messages are unencrypted and there is no sense of privacy, and that admins have full visibility and can do what they want with them.
> Agreed, but that admin is breaking his promise, duty, responsibility (call it what you will) if they then upload these messages to an LLM for evaluation.
There is **no** promise, duty, or responsibility that an admin has beyond legal and what they themselves promise. The fediverse is great in that if you disagree with your admin, you are free to leave and choose a different one.
As for GDPR, feel free to argue it, but when it's claimed at every turn that messaging is unencrypted and basically open, well, I don't think it'd hold up. It literally says to go use Matrix or something else.

