The software giant said the XCP copy protection system counted as malicious software under the rules it uses to define what Windows should be protected against. It is planning to include detection and removal tools for XCP in its weekly update to its anti-spyware software. The news came as Sony BMG suspended production of CDs that use XCP. Microsoft's decision to label the XCP system spyware was revealed on the corporate blog maintained by the software maker's anti-malware team. Malware is the generic term for malicious software and includes viruses, spyware and any other program designed to hijack or harm a computer. Writing in the blog, Jason Garms, one of the senior managers in the anti-malware team, said the XCP software qualified as spyware under the "objective criteria" Microsoft uses to assess potentially malicious programs.
I don't think this is a Microsoft stand against Sony, or against "digital rights management" gone too far, or even against malware. I think they're just protecting their investment of installed operating systems, which happens to coincide with the users best interests. If attempted removal of the Sony code disables the CD drive, you can't install a new Microsoft OS. Microsoft get public support for this but they're the only ones that can initiate wholesale removal of the Sony program, and they have the knowledge to do it properly, at least in theory.