I'm a bit confused, how does locking down a single community help?
Are the spammers really just focusing on one community instead of switching to the next after it gets banned?
I do hope there is an IP ban option, so someone can't just use the same IP again to create an account on another instance and post CSAM from there. Obviously I do know about VPNs, but it makes it a tiny bit more difficult to spam in large amounts.