PII includes any information that can be used to link or correlate personal information. That includes usernames and account IDs. Every like/upvote contains that information, as well as a timestamp, indicating a unique account but also behaviour. The system doesn’t just share a list of names, it shares a list of names with a lot of context. Stuff like this is also why pseudonymisation isn’t sufficient to avoid GDPR obligations.
Usernames aren’t sensitive information, so you can handle it without too much special care (although you do need to ensure basic protection of login credentials against data leaks, for instance by encrypting databases as a minimum requirement). They are PII, though, which means you’re obligated to take some level of care and ensure that the information can be corrected or redacted everywhere.
The GDPR simply wasn’t written with something like the Fediverse in mind. My server knowing when your account upvoted what posts on a third server would be ridiculous if we’re talking about Twitter and Facebook, but it’s the core of vote counting on Lemmy.
Mastodon and Lemmy don’t actually share any data actually protected by GDPR, unless the users actively make it public (like using their real name).
PII includes any information that can be used to link or correlate personal information. That includes usernames and account IDs. Every like/upvote contains that information, as well as a timestamp, indicating a unique account but also behaviour. The system doesn’t just share a list of names, it shares a list of names with a lot of context. Stuff like this is also why pseudonymisation isn’t sufficient to avoid GDPR obligations.
Usernames aren’t sensitive information, so you can handle it without too much special care (although you do need to ensure basic protection of login credentials against data leaks, for instance by encrypting databases as a minimum requirement). They are PII, though, which means you’re obligated to take some level of care and ensure that the information can be corrected or redacted everywhere.
The GDPR simply wasn’t written with something like the Fediverse in mind. My server knowing when your account upvoted what posts on a third server would be ridiculous if we’re talking about Twitter and Facebook, but it’s the core of vote counting on Lemmy.