Open source is based on contracts, licenses between buyers (or users) and sellers (or projects). These are just as valid, and just as important, as the contracts of proprietary companies. Government protects both equally.
Copyrights and patents are monopolies both sides depend on for their existence. In American law they're based on Article I, Section 8 of the Constitution, which calls for them to be granted for limited times to encourage innovation.
To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries;
It's right up there with coining money and maintaining a Navy.
So the idea that the U.S. Justice Department is taking another look at Microsoft's financial engineering of Novell's Linux patents into its own hands is perfectly legitimate, and very much in keeping with the purpose behind the principle of patents Microsoft wants upheld. Microsoft already claims to control Linux, an operating system whose creation it fought each step of the way, through patents. It has never disclosed the specific Microsoft patents it claimed Novell violated in its 2006 patent agreement. Now that it owns, through a Microsoft-designed consortium called CPTN, the rest of Novell's Linux property, it could in theory kill Linux entirely.
It's not black letter law. But it's the purpose behind the law the Justice Department is trying to protect. It's important work. The hope is that Microsoft will agree to only use the rights it's buying “defensively,” allowing it to compete directly in the Linux market. And that could be legally enforceable, by both the government and private parties.
And that agreement, when it comes, needs to be binding on the other CPTN partners too. I wouldn't trust Oracle CEO Larry Ellison any further than I can throw him. The same for Apple and EMC.
Just remember, legal fans. The purpose of the law is more important than any legal argument, indeed than any legal claim of rights. When the letter of the law conflicts with its purpose, government has an absolute obligation to protect the purpose first.