Calling Ballmer's Bluff
This was something I was going to write about, but someone has gone one better and come up with an entire site devoted to the idea:
Open Letter to Steven Ballmer
It's come to many in the Linux community’s attention you have claimed again and again, that Linux violates Microsoft's intellectual property. Not only that, but it's been reported Microsoft has convinced businesses to pay for a Linux patent that you can't provide.
Therefore, this website will serve as a response to this accusation, and within it, a request. The request is simple, since you, Microsoft, claim to be so sure of yourself: Show Us the Code.
Show us the code, indeed.