I listened to Cory Doctorow's reading of A Cost Analysis of Windows Vista Content Protection by Peter Gutmann. There are so many jaw-dropping passages in this paper that I thought a little collection of quotes would be useful for people who don't want to read the whole thing.
Windows Vista includes an extensive reworking of core OS elements in order to provide content protection for so-called "premium content", typically HD data from Blu-Ray and HD-DVD sources. Providing this protection incurs considerable costs in terms of system performance, system stability, technical support overhead, and hardware and software cost. These issues affect not only users of Vista but the entire PC industry, since the effects of the protection measures extend to cover all hardware and software that will ever come into contact with Vista, even if it's not used directly with Vista (for example hardware in a Macintosh computer or on a Linux server).
In fact so far no-one has been able to identify any Windows system that will actually play HD content in HD quality, in all cases any attempt to do this produced either no output or a message that it was blocked by content protection.
In fact, Microsoft is imposing a higher standard of security for premium content than what's been required in the past for any known secure computing initiative proposed for protecting data classified at TOP SECRET or TS/SCI levels… Just to make this point clear, the level of security that Vista is trying to achieve to protect video and audio is more extreme than anything the US government has ever considered necessary for protecting its most sensitive classified data.
In the introduction, I predicted that Vista's content protection, the entire mass of complex and troublesome technology covered in this writeup, would last less than a week once the hackers got hold of it. Sure enough, shortly after Vista's release, it was broken by an individual who was annoyed by the fact that he couldn't play back his legitimately-purchased HD-DVDs on his legitimately-purchased HD-DVD player… As a result, both HD-DVD and Blu-Ray content can now be decrypted and played without image downgrading or blocking by the OS, and unprotected content is already appearing in the usual locations like BitTorrent streams. The fact that the legally-purchased content wouldn't play on a legally-purchased player because the content protection got in the way was the motivating factor for the crack. The time taken was about a week. As a result, all of the content-protection technology (at least for HD-DVDs and Blu-Ray discs) is rendered useless. All that remains is the burden to the consumer.