How will Lemmy handle illegal content like drug dealing, child porn, snuff movies etc? On Reddit, the corporation is accountable so they will make an effort to ensure non of this exists on their platform. And they would face legal troubles if they failed to act.
But as Lemmy is decentralised this isn’t really possible. Sure the main instances can defederate from bad instances, but those instances could still operate and be accessible on the web. Especially if they’re hosted in countries outside of the western sphere of influence. Multiple bad instances could federate and duplicate the illegal content pretty easily, making it difficult for the authorities to keep it shut down. Has this been thought about already?
Im sure it would be easy to track on behalf of authorities, no more than downloading a large zip and uploading it elsewhere is. Authorities can notice the unique characteristics of files and find them across the web.
As for actually stopping this, right now a lot of instances federate with many instances, I’d be worried about bad actors fwderating with big instances and then posting illegal shit, meaning big instances download onto their servers by accident. More moderation tools need to be developed into fedi.