The big platforms always use a variety of solutions. Always some kind of database of hashes of known CSAM available via an API. Always human beings on a trust a

The big platforms always use a variety of solutions. Always some kind of database of hashes of known CSAM available via an API. Always human beings on a trust and safety team. Takes considerable time, money, and emotional toll. Not just anyone can access all of the SaaS databases and it's approved on a case-by-case basis. Obviously not all CSAM is in these databases, and gen AI output adds another hurdle to preventing this kind of malicious behaviour. Personally, I feel a potential solution could be that user clients could opt into referencing hashes of media before it is downloaded, and that could either be handled by their home server, or a third-party. However, something like that is really idealism and not realistic at this point, despite being a great solution in a perfect world where people maintain encryption, yet don't expose themselves to CSAM inadvertently. In terms of the Matrix.org homeserver, perhaps an alternative (though would prove unpopular) is only allowing Matrix.org users to upload media if they're a paying supporter of the Matrix.org homeserver with a valid payment method on their account, thus obviously linking their identity to their account. https://matrix.org/membership/ https://matrix.org/membership/ The knock-on effect would be that it may offload some users onto their own infrastructure and alleviate the moneypit of a public instance, or directly fund the public instance itself if they do choose to support it financially. The Matrix.org instance doesn't support users adding bridges, so it isn't that much of a stretch to forbid media uploads from non-supporters. Portable identities would make this a no-brainer, but even without them, I still feel as if the public instance is largely an incredibly generous demo to help folks take Matrix for a spin. Decentralisation is such a major selling point that's vastly underutilized. I do think that people should at least attempt to become decentralized and manage their own community by themselves, be it public or private. Large public homeservers are always going to be considerable targets for this kind of problem. It's a lot of digital eggs in one digital basket for a lot of reasons. Nothing stopping people uploading images onto a third-party file storage system and providing the URL if they absolutely need to share a screenshot or similar on the public Matrix.org instance. Anyway, fleeting thoughts.