This Ars Tecnica article talks about the story, which is fairly well-known by now; Microsoft security people loaded incompetent code into their anti-piracy server (gratuitously named "(MS)Windows Genuine Advantage", when it clearly gives the user no advantage, only Microsoft). The fiasco left an estimate twelve thousand Vista users with "invalid" installations, honest users basically accused of software piracy and unable fully to use the software they (over-)paid for. Maybe next time some of them will use BSD, Linux or Mac OS X, which don't depend on a central server administered by people who think every user is out to rip them off.

ROFL department: What's even funnier is that when I viewed the Ars Tecnica post, the paid ad from Microsoft was "Linux vs Windows: Which do you choose when reliability is key? Get the facts." Thank you, Microsoft, but I believe the WGA fiasco contains all the facts one needs to decide, and, err, it won't be in your favour...