If someone posts a link, and that domain contains a nostr.json, the keys in there should be used to determine zap targets. (zap to _ passing the url for zap routing)

This way you can have things where people can just point to the media elsewhere and there's the clear distinction between if you're zapping the poster or the hoster (pardon the rhyme) who is presumably linked to the creator in some way.

Some of the webfinger stuff might make this easier, but the ln address should ultimately come from some pubkey