Shall we start using the invite-obly relays technique? Let's suppose that I have a relay: I'm willing to accept new pubkeys to use my relay only if they're invited directly by one of my already-subscribed pubkeys. Lets's put a 2 or 3 maximum invites per pubkey.

In this way we would have a relay in which only "known people" hang out, no bots, no fkng harassments. 

Just a trash idea maybe, because content discovery would be much restricted.