Microsoft, after having failed to successfully patch their copy protection system that was recently cracked, is now suing the anonymous creator of the FairUse4WM system. They're not suing him for circumventing the copy protection, but rather claiming that he must have access to proprietary Microsoft source code in order to do what he's done. Read more.
What is FairUse4WM? (In a nutshell, FairUse4WM strips Windows Media DRM!)
Microsoft Demands Web Site Owners Take Down FairUse4WM sites!