Reports of people having trouble with the new BD+ copy protection are starting to surface. The movies in question are Fox's Blu-ray releases of "The Day After Tomorrow" and "Fantastic Four: Rise of the Silver Surfer."
BD+ is an extra layer of copy protection. With it, Sony should be able to change the keys used to unlock it. In short, this means that if a BD+ disc is hacked and copied, Sony can change the keys that secure future discs from being copied.
All in all, a good idea. However, reports of difficulties playing these BD+ protected Blu-ray releases are starting to surface.