Next week, new HD DVD movies will hit the shelves that won"t play on some players, the first countermeasure by the content and software industries to combat intensive efforts by hackers to break copy-protection technology.

The move comes four months after hackers first poked a hole in AACS (Advanced Access Content System), the complex encryption scheme used to protect HD DVD and Blu-ray Discs. In the interim, they"ve been able to decrypt HD DVD movies and, theoretically, upload them to file-sharing networks.

The development, disclosed on the Doom9.org forum for video technology aficionados, ironically involved the use of an HD DVD add-on drive for the Xbox 360, the gaming system from Microsoft, one of the backers of the AACS system.