Well well well. The industry tried their best to make the new competing high definition formats blue-ray and hd-dvd as secure as possible so that no one would be able to view them with insecure hardware or would be able to copy the movies. The files themselves are protected by AACS which stands for Advanced Access Content System. HDCP (High-Bandwidth Digital Content Protection) makes sure that high definition playback is only available if the output device (television, monitor) is HDCP capable, if not the movie will be downsampled to 960×540p.
