New DVD formats HD-DVD and Blu Ray use DRM to prevent disc copying. It's been cracked with BackupHDDVD. The video formats use AACS encryption. Computer security experts Ed Felten and Alex Halderman show how AACS works and how it can be attacked. They say it's unlikely the movie studios will be able to plug this hole. They conclude "[BackupHDDVD] isn't a big deal by itself, but it is the first step in the meltdown of AACS."