It'd be neat if we had software relay operators could run that would crawl all npubs in their database (it could behave just like any other client requesting notes) and assign something like a "trust score" to each. It could use some web of trust heuristics and spam reports, possibly seeded by a few well established users. Relay operators could then use those scores for spam filtering or cleanup jobs deleting high probability spam. The main benefit is this would be a generic tool any admin can run regardless of how their server is implemented. Does this exist? #asknostr