Any feature relying on a willing cooperation of every node in the network is impossible to enforce.

Sure, it should be attempted, but don’t expect it to actually matter against actors that just don’t give a fuck.

As a general note, the design of Lemmy is around preserving information against censorship over having private conversations (like Matrix for example). You're probably aware that once data is delivered to other servers, the origin server can't guarantee deletions of data from them.

I'm not an admin, but I remember that Lemmy admins are able to purge content from their server, and send out a request for other servers to purge their copy of data which by default would be accepted if received from the canonical server. This was used to remove some harmful content that was posted on Lemmy a few times. This feature isn't user accessible, at least as of now.

Media uploaded to Lemmy by the user can be deleted.

Edits are propagated through federation, so if you are concerned, you can edit posts you want to delete before deleting them which is close enough.

I am not a programmer, but as I understand how it works, when you access content (user profile, post, etc.) that is not on your server, a request is sent and two things can happen. The request receives a response and the content is updated or it is not received and you see a cached version. I suppose a third option could be added, you get a response and it says that the content is actively deleted, causing the cache to be deleted. Maybe it took a while to clear everywhere, but I don't see why it wouldn't work.

The solution: A three‑layer deletion model This is the only model that satisfies both Lemmy’s architecture and user expectations.

Layer 1 — Local hard deletion (guaranteed) When a user deletes a post/comment:

the content is wiped from their home server

the object can remain as a placeholder to preserve thread structure

media files are fully removed

This part is already possible.

Layer 2 — Federated delete signal (best‑effort) When deletion happens, the home server sends a message:

“This content is deleted — purge your copy.”

Servers that respect federation will:

delete their cached copy

update the thread

remove the content from search

Servers that don’t care will ignore it — but that’s already true today.

This is the missing piece Lemmy needs to implement.

Layer 3 — User‑initiated purge request (optional escalation) Admins already have a purge tool that:

deletes content locally

sends a federated purge request

is accepted by most servers

Expose this to users in a controlled way:

rate‑limited

confirmation required

optional admin approval

This gives users real deletion power without enabling abuse.