The developers of LemmyNet are being asked for the ability to define a subroutine by which uploaded images are to be preprocessed and denied or passed thereafter. There is no such feature right now. Even if they wanted to use CloudFlare CSAM protection, they couldn’t. That’s the entire problem. This preprocessing routine could use Microsoft PhotoDNA and Google CSAI, it could use a self-hosted alternative as db0 desires or it could even be your own custom solution that doesn’t destroy, but stores CSAM on a computer you own and stops it from being posted.