I'm on iris and to be clear I've don't see spams in global feed. Only on post's that I'm commenting on.
Discussion
Clients are pretty much doing a good job content filtering the global feed. However I think lower-level responses and comments over legitimate posts may need checks. I may have to check what relays that spam bot uses. Probably a paid relay filter could help eliminate it.
Just checked. The bot is connected to a total of 33 relays of which 3 are paid relays (including mine). However, the public key is not subscribed/admitted to my paid relay so they can’t write to it.
I also verified that they are not admitted to nostr.watch and eden.land.
So, a paid relay filter would work fine as long as clients also filter comments/responses.