Are you suggesting shifting all of this work onto the relays? That would give relays yet another attack surface - they could simply be DDoSed through it. And in any case, a blacklist is the worst possible approach. If a client really wants to protect itself, it should use a whitelist instead. Gener...

Maybe you are correct, but I take it for a fact that most people will use a client and never run their own relays, so client-side would be the only option. Clients can set their own limits not to handle thousands of comments and mentions, use helpers like PoW, and if user doesn't want to see random...