You purchased video files from iTunes Store, or iTunes movies rentals, they are all DRM-Protected. If you don't remove itunes DRM Protection, it's impossible to play them on any Apple incompatible devices, like Zune, Creative Zen, PSP, mobile Phone, etc. This turns out really bad if you want to buy a new mp3 player which is not manufactured by Apple.
With this DRM Removal software, you can remove Drm from iTunes M4V movies and music videos and save as MOV, MP4, unprotected M4V for iPod, PSP or MP4 player, etc. Works perfect.