In principle "who owns this jpeg" is just a few bits in a distributed filesystem that the community collectively agrees to treat as the canonical source of "ownership", and they could easily roll it back if someone stole a market-distorting amount of art.
In practice, if you do an interesting heist -- like you put on cool looking art thief costume and livestream yourself on a vintage PowerBook bypassing the owners' defenses and nabbing the apes with a narrow escape -- you've written a compelling story that the community is sort of bound to accept.