Dan Goodin in The Register:
A lone hacker has unlocked the master key preventing the copying of high-definition DVDs in a development that is sure to get the entertainment industry’s knickers wrapped tighter than a magnet’s coil. What’s more, the individual was able to defeat the technology with no cracking tools or reverse engineering, despite the millions of dollars and many years engineers put into developing the AACS (Advanced Access Content System) for locking down high-definition video.
A hacker going by the name arnezami on the Doom9 discussion boards, has been hard at work for at least the past eight days, when he first claimed to have discovered how to read the volume ID of the movie King Kong. Over the coming days, he documented his progress, with the Eureka moment occurring on Sunday, when he was able to confirm the validity of his method for identifying the processing key. Combining the two allowed him to unlock the copy protection.
After getting some much-needed sleep, arnezami was back to explain how he accomplished his feat. While his player loaded the Kong disc, he closely looked for changes being made to a certain part of his computer memory. Making a memdump with the WinHex file editor, he was about to find the key fairly easily.
More here.