So in quite an entertaining move, Microsoft is going after 235 F/OSS projects for various patent violations, now...I'm not supporting or arguing with the lawsuit as I am certainly not a lawyer. However, as a slashdot user has pointed out...
In the article, it explains why Microsoft chose this route: Since FOSS is (nominally, if not practically) written by a loose band of volunteers, and because they don't really sell the software (with some exceptions, but generally mostly they give the software away and sell the support), it is extremely difficult to track them all down and make them pay royalties. It is much easier to just threaten the major corporate users (who are extremely risk averse). To quote Neal Stephenson, "Microsoft is ten times smarter than your average government, a hundred times more aggressive, and bound by no particular rules."
In the old days, we called this extortion.
It will be an interesting one here, thats for sure. But you can't argue too much with that logic, it could go way too well in Microsoft's favor.

