Proving compliance can be extremely difficult for large companies, especially those that have grown thru mergers and acquisitions. The companies being acquired may not have adequate documentation for their software assets.

Consider some possible states of software: volume licenses, retail purchases, bundled with a PC, and unlicensed. Add to that the fact that Microsoft is not the only vendor of software licenses - you may also have agreements with Novell, Adobe, Lotus, Business Objects, McAfee or Symantec. And what about equipment that is retired, should those licenses be added back into the available license pool?

That being said, I agree that MS is going overboard with their compliance efforts. At a time when Vista and Office 2007 are NOT selling like crazy, they should be making it easier on their customers, not harder.