"This is simply the movie industry's latest attempt to sugar coat DRM (Digital Rights Management). You already bought the movie. You should be able to watch it on any device you own that can show the movie and back it up. Of course, that's the last thing the movie companies want you to do. As far as they're concerned, you don't buy a movie, an episode of a TV show, an album, or song. You rent the use of it on one, or at most, two, devices.
"Here's how Digital Copy works. Twentieth Century Fox and Apple introduced Digital Copy for iTunes earlier this year. It uses Apple's FairPlay DRM to lock down the video on the Digital Copy. Since then, Disney and Lions Gate also have started to use it. The Digital Copy can be transferred to a Windows PC or Macintosh and viewed with Windows Media Player or iTunes. You can also transfer the movie to an iPod, Apple TV or a compatible Windows Media-based portable player."
