Have managed to hack together a very rudimentary integration between Open Media Match (Hasher-Matcher-Actioner / HMA) and Mastodon. This can act something like IFTAS CCS but for your own infrastructure.

Yes, it does mean running software incubated at Meta, but the alternative is buying from a provider like Thorn or reimplementing the entire hash & match software.

This is just a proof of concept, similar to the prototype by Juliet Shen (julietshen.bsky.social) for AT Protocol services.

This would allow hash & match for CSAM against the NCMEC hash database and NCII against the StopNCII hash database.

This isn't a production thing, just a proof of concept, it's not deployed anywhere. The only thing that HMA receives is the media file to hash.

Here I've manually loaded up that cat picture into an instance of HMA that I have running locally, and show that when that content is posted or reblogged by a local user, the hash is calculated, and if there's a match, it creates a report via the mastodon API.

https://github.com/facebook/ThreatExchange/tree/main/hasher-matcher-actioner