"ZDNet's Hardware 2.0 blog is reporting that new copy-protection software for DVD publishers from a company called ProtectDisc not only makes it difficult to rip movies that you've purchased but also prevents discs from playing in a Windows PC at all. From the article: 'Protect DVD-Video is the brainchild of a company called ProtectDisc. Part of the copy-protection mechanism is a non-standard UDF (Universal Disc Format) file system which results in the IFO file on the DVD (this is the file responsible for storing information on chapters, subtitles and audio tracks) appearing to the PC as being zero bytes long.'"
If I come across such a DVD, I will probably be returning it as being defective goods. Because that's exactly what it is.
And Trading Standards has some large sticks they can use against companies who knowingly sell and/or manufacture defective goods.