I can also answer some questions, but mostly Kirah can answer them!
current policy seems fine tbh, if that happens to somebody and they really want to use that picture, they can just edit it a little. it's not like any lawyer in the world would take that to court.
The only policy I can imagine for that is for people to provide credit and sources for all of their pictures. But what's the point? The issue barely ever comes up, and if someone really wants to find those images they can use a reverse image search. It's not RP posts from years ago stealing money from online artists. They should spend the time they use hunting down "unauthorized" usages of their images and get a job if money is what they're concerned about.