On a BD-ROM disc, there will be three levels of content protection, Advanced Access Content System (AACS), an experimental additional DRM mechanism called BD+ and a hidden undetectable mark known as a ROM Mark. A ROM Mark will exist on movies, games and other data discs to help prevent mass production piracy and sale of unauthorized copies. It will be a unique identifier on each pressed disc that can link it back to the very machine that produced it.
This will allow customs enforcement to determine between real and counterfeit copies of copyrighted works. Special players will be able to check the code on the disc, where it should be and where it is detected. Developers of the technology believe it can stop wide scale piracy, and that to beat it, pirates would have to crack the system completely which would take a lot of time and resources. Not many details are currently available on how a ROM Mark would affect (if it does) consumers' digital rights.