Still plowing through Van Lindberg's excellent book on open-source software law, and he discusses a court case that I somehow missed in three years of law school.
Van references IBM's efforts to keep PC clones out of the market. IBM apparently made its BIOS information (and source code) widely available as a way to poison the well. In other words, any engineers who saw the BIOS code and then attempted to reverse engineer it would be in violation of IBM's copyrights.
Hmm....While I believe Microsoft made its protocols available for public inspection due to pressure from the European Commission, the effect on developers is very similar to the IBM BIOS case. If I use the Microsoft documentation to reverse engineer or otherwise integrate Microsoft code or ideas into my own, I'm highly susceptible to a lawsuit.
This is why making information freely available, without associated IP grants freely available, perhaps does more harm than good. Code without rights is a lawsuit waiting to happen.