Well, now they do.
The good news is that the Linux Foundation has started the Open Compliance Program, a comprehensive initiative to help companies and developers comply with open-source licenses. There are also other groups like the Open Invention Network trying to defend against patent attacks on Linux and businesses like Black Duck Software and Palamida that can help independent software vendors and other businesses block IP attacks.
The bad news is that IP attacks are now more of a worry for open-source developers than they have been before. SCO's feeble attacks on Linux were a sideshow. Oracle's patents attack is far more worrisome.