Yeah, fishcake implimented AI to detect csam at nostr.build, but also theres an fbi database of md5 hashes of known csam images that all US based image hosts are required to filter images through. This would be good for nostr image hosts to voluntarily impliment.

Its important to stress to new users, nostr notes are just text. They link to images srored on media servers. So censoring notes at the client or relay level is not the best approach, imo.