It’s not surprising that ChatGPT has been accused of breaching the EU’s main privacy law – PIA blog noted that ChatGPT was a privacy disaster waiting to happen back in February. As the first complaint to be taken up by an EU data protection agency, this case will be watched closely by other EU Member States, and around the world. The Polish inquiry is likely to investigate many of the key GDPR issues that arise for AI programs and be used as a benchmark in future legal cases.
Your username would fall under GDPR as personally identifiable information - also if your instance asks for an email address, that is also personally identifiable information under GDPR.
I think any posts that users can contribute to a social network, also fall under GDPR.
This is a potential issue that many instance owners may not have realised.
Even if it is, this data is not processed in a way that would violate the law, unless the hosting party is doing something shady. It would be an incredible stretch to consider that a website only asking for a username to attach to a user somehow violates GDPR.
Well for one thing a user is prevented from deleting their account when banned. I’m pretty sure this can be considered a violation of the law.
Email works the same way. Once your data is received by the other party, you cannot delete it.
Public mailing lists have a very similar behaviour to the fediverse’s. I am not aware of any credible GDPR cases against those, although it may happen down the line, we’ll see.