Impostor identification idea:
If any two people on nostr dare use the same username with the same picture, it's quite obvious that the user that came later is the impostor.
Of course you don't want your client to check every posts' user to see if there is an older user out there with that Username+Pic by default... That would be a lot of needless requests.
-But how many impostors would go out and get verified by a paid service like NostrVerified or Nostr-check? That would cost sats, so it would be a perfect wast of money.
Therefore, clients could simply do a username+Pic check on all non-verified(paid) accounts. That should put an end to impostors here in a way that OldBirdApp never had.