So, I download the latest Hollywood blockbuster, re-title it giving it an absurd name, removing credits/publisher marks and maybe blurring/replacing the lead's face. Then I re-upload 'Deep Groat: Sub-Prime Deposit' (a.k.a Catwoman -it's a modern classic) on the Pirate Bay.
Our good UK subject comes along, downloads it and thinks 'Never heard of this!?' No idea who made it, no way of finding out.
That 'film' is now in the public domain?