how would you approach this problem @fiatjaf ? seems a lot different than the twitter way of using follow lists to avoiding spam. I'm leaning toward a few servers run by different people for redundancy/weak censorship resistance, but they all would be required to have heavy anti-spam protections and maybe even shared spam ip blocklists. could just make it stackernews style and require payment for every interaction, but I feel like that is too limiting.

The best approach (and to me the only that doesn't have crucial flaws) I could think of is still the NIP-29 one: groups are identified by a random id and can have owners and mods and rules, but the rules are enforced by a specific trusted relay. So in fact a group "address" is given by id+relay. If the relay goes offline or become evil groups can just move to a different relay. Anyone can also fork the group by reusing its id but defining a different relay that accepts the new ownership.