I could be wrong though

Anyone telling you they’ll delete your data from the internet without clarifying that it is in fact impossible, is at worst deliberately lying to you usually for their own benefit, and at best making a promise they literally have zero ability to keep.

I would hope that Fediverse services will never lie to you and tell you your data is deleted, because it can’t be.

It doesn’t even take a malicious actor: I am working on a local-first browser extension that is very aggressive about caching content in the database. There is no “please delete this data” for an extension. You of all people should not be making claims about privacy that you know you can not guarantee.

• If your instance shuts down, there is no way for you to generate delete requests
• If a server admin has to restore a backup from before your request, the deleted data will be restored
• Immature or experimental software may not work as designed; Lemmy itself has a version number starting with 0
• Archiving services may keep snapshots of pages from fediverse servers; here’s your user page on lemmy.world on archive.org
• Fediverse servers often make content available by RSS, and RSS clients may store that content; there’s no way for them to receive a signal that it should be deleted

And then there’s malicious activity. It wouldn’t be hard to run a server that speaks ActivityPub, subscribes to a bunch of stuff, pretends to honor delete requests, and actually keeps everything.

Deletion will always be unreliable on the fediverse as long as it runs on technology that looks anything like current implementations.

Anything federated is public information.

Data like IP, email etc. is deleted.

PieFed sends delete requests to every known server, including defederated ones. I’ve seen a ton of delete requests from Mastodon too, for accounts that don’t exist on PieFed so it looks like Mastodon does that too. No idea about other fedi platforms.

If you make a post, that is federated to all kinds of other instances. They might process your delete request, or they might just ignore it and keep old posts stored for as long as they want. It’s the same with if you make a post on Reddit, someone sends that thread’s URL to the Internet Archive, and now there’s a permanent record of your account there.

If you post publicly, expect it will be recorded by someone publicly viewing it, and it will not be guaranteed to be removed.

Don’t fall for the illusion of privacy that the proprietary networks give you: there are people that copy data from reddit just for the fun of it. Always assume that anything you publish online is publicly available.