Relays are already blocking massive numbers of accounts. If they weren't NOSTR would be a spam filled wasteland. NOSTR.band has sophisticated spam filtering techniques based on pagerank type algorithms and "trusted" users. This is why their feed is basically "clean". Your question might be if relays will ban users based on the report from One other user, or based on multiple reports. I think relays and clients are already banning many users based on One or multiple reports. For instance Child Porn is banned instantly by any good client or relay. Clients or relays who don't ban criminal behaviour will not succeed. #grownostr