Microsoft

I always had a bad feeling about the whole concept of the Protected Mode Process in Vista. It is designed to help DRM authors but in the long run it might be used for 'bad things'. Thankfully, 64-bit is "locked down" better because it doesn't have the 'legacy crutch' to keep alive.

You can read about it here. Very smart guy. MS really should have him on their kernel team and not Apple.