It would end up being an interesting battle to see who starved first out of the copyright holders and the music/video sites. The day after this perfect enforce

It would end up being an interesting battle to see who starved first out of the copyright holders and the music/video sites. The day after this perfect enforcement came into effect users would still flock to Youtube/etc hoping to find the latest content. So if the a copyright holder decided to block all their content they would lose a lot of attention in the initial stages. However would the users continue to flock to youtube/etc without all that copyright content? No doubt the copyright holders would soon revamp the 'official sources' of their content. These would most likely still be restrictive/costly/sucky but as the only source of that content they might stand a chance of drawing the audience back from the 'free' sources. I'm not sure who I'd bet on in an 'all out war' but it most likely wouldn't come to that with copyright holders forced to allow a least some of their material on the sites with the existing audience. I do believe however that it would shift the balance of power back towards the copyright holders.