cross-posted from: https://lemmy.ca/post/4273025
Someone made a tool to remove CSAM content automatically: https://github.com/db0/lemmy-safety
You can upload images to a Lemmy instance without anyone knowing that the image is there if the admins are not regularly checking their pictrs database.
To do this, you create a post on any Lemmy instance, upload an image, and never click the "Create" button. The post is never created but the image is uploaded. Because the post isn't created, nobody knows that the image is uploaded.
You can also go to any post, upload a picture in the comment, copy the URL and never post the comment. You can also upload an image as your avatar or banner and just close the tab. The image will still reside in the server.
You can (possibly) do the same with community icons and banners.
Why does this matter?
Because anyone can upload illegal images without the admin knowing and the admin will be liable for it. With everything that has been going on lately, I wanted to remind all of you about this. Don't think that disabling cache is enough. Bad actors can secretly stash illegal images on your Lemmy instance if you aren't checking!
These bad actors can then share these links around and you would never know! They can report it to the FBI and if you haven't taken it down (because you did not know) for a certain period, say goodbye to your instance and see you in court.
Only your backend admins who have access to the database (or object storage or whatever) can check this, meaning non-backend admins and moderators WILL NOT BE ABLE TO MONITOR THESE, and regular users WILL NOT BE ABLE TO REPORT THESE.
Aren't these images deleted if they aren't used for the post/comment/banner/avatar/icon?
NOPE! The image actually stays uploaded! Lemmy doesn't check if the images are used! Try it out yourself. Just make sure to copy the link by copying the link text or copying it by clicking the image then "copy image link".
How come this hasn't been addressed before?
I don't know. I am fairly certain that this has been brought up before. Nobody paid attention but I'm bringing it up again after all the shit that happened in the past week. I can't even find it on the GitHub issue tracker.
I'm an instance administrator, what the fuck do I do?
Check your pictrs images (good luck) or nuke it. Disable pictrs, restrict sign ups, or watch your database like a hawk. You can also delete your instance.
Good luck.
Absolutely worth nothing.
To be honest, it's ludicrous that these things can easily get you embroiled in criminal cases. If someone walks into my corner shop and hides a murder weapon on a shelf, it ain't my fault.
Not the first time.
But if you've got a Murder Club for Murderers that meets nightly in the 2000sqft supply closet to plan the next round of murdering, while keeping a small armory of bloody axes on the shelf, the DA is going to prosecute you as an accessory regardless of how much you officially knew.
Because plausible deniability is so easy with web hosting, and proliferation is trivial, the only way to look like you're touch on this shit is to stomp down extra hard on everything you see.
Nevermind the swarm of cockroaches in the walls, we need the biggest splatter possible on the one we catch in the living room.
If the feds want to go through a folder chapos have been using as a anonymous file host for the past 4 years I say good luck and have fun with that.
There is probably upwards of 200 forgotten ppb variants in there.
Seems like it would be an easy bug to fix. You'd just need to implement a pre post cache server side and then move the image to the pictrs database when the post is actually posted
I am pretty sure @makotech222@hexbear.net and the rest of the hackerman knew about this for years.
They knew we were using it to add images to comments. They probably decided it was low priority or no threat at all.
yeah we brought it up to lemmy devs when we were finishing our prep for migration, but nothing came of it really. I have improvements in mind, but haven't summoned to willpower to start coding in rust again
Lots of us have been using this to host images (for use on hexbear) since like day 1. Lol
Is was super common when we didn't have the ability to upload images to comments.
Yeah I did this all the time before we got image embeds
I've been doing that for years, always thought it was weird. Used it to put images in comments back before hexbear updated to this version.
