There have been users spamming CSAM content in !lemmyshitpost@lemmy.world causing it to federate to other instances. If your instance is subscribed to this community, you should take action to rectify it immediately. I recommend performing a hard delete via command line on the server.
I deleted every image from the past 24 hours personally, using the following command: sudo find /srv/lemmy/example.com/volumes/pictrs/files -type f -ctime -1 -exec shred {} \;
Note: Your local jurisdiction may impose a duty to report or other obligations. Check with these, but always prioritize ensuring that the content does not continue to be served.
Update
Apparently the Lemmy Shitpost community is shut down as of now.
Yeah... Just wow. I disabled pictrs and deleted all its images, which also means all my community images/uploaded images are gone, and it's more of a hassle to see other people's images, but in the end I think it's worth it.
Through caching every image pictrs was also taking up a massive amount of space on my Pi, which I also use for Nextcloud. So that's another plus!
There has to be a more elegant way of dealing with this in the future, like de-coupling between Lemmy-account hosting (which effectively means acitivypub-fediverse account) and Lemmy-communities hosting.