The remedy, in other words, remains legal. I see this as a tool for facilitating legal remedy. (Or have I missed your point completely?)
That's not enough. What if someone publishes before the author. Say I buy something from other resource or even directly and publish it on the OP's.
I don't see the way how this could be implemented to blockchain. If every blockchain node downloaded and compared all images It would create massive bandwith and need for cpu/gpu power. Or am I missing something?
Look at Steemit for examples of people making money from original content.