I have already commented on the Jacobsen case, which ruled on the enforceability of the copyright licenses of Free (open source) Software licenses, making an equivalence between the monetary consideration of proprietary licenses with the operative restrictions and conditions of Free Software licenses. Lawrence Rosen, one of the world's top experts in Free and Open Source Software and former general counsel of the Open Source Initiative, has published an interesting article on the same decision, which tells us more on the subject.
I invite you to read and peruse the article. A copy of which is also available here below for download. The paper is under the Open Software License (OSL 3.0).