tl;dr: Scenario: Studio sends 10ks advanced copies of their film to reviewers before screening. One of them gets leaked. They want to know who leaked it. Custos

tl;dr: Scenario: Studio sends 10ks advanced copies of their film to reviewers before screening. One of them gets leaked. They want to know who leaked it. Custos embeds a "watermark" in the copies that contains a private key of a bitcoin wallet containing 5$. Each copy has a different wallet. When anyone down the pirate chain decides to take the money, Custos knows who the leaking source was. Benefit over traditional watermarks is that they only have to monitor the wallets. IMO this is quite a clever idea because even after pirates start scrubbing the key off, there will always be an incentive to claim the money, perhaps much later when someone can get many of them at once. It will seed distrust that'll be hard to weed out.