Earlier in this series of blogicles regarding the 3rd draft of the GPLv3 open source license, attorney Ed Walsh cautioned those who are considering using this license should it become final while incorporating certain provisions of section 11 (Patents). These provisions are a response to the Microsoft-Novell deal regarding patent licenses and software distribution.
Others have weighed in with similar observations. The Association for Competitive Technology has published white papers extremely critical of the new draft. These publications provide a legal analysis of the relevant portions of section 11 of the latest GPLv3 draft. ACT has published Richard Wilder's white paper, "GPLv3: The Legal Risks of Overreaching for Third Party Patent Rights."
Wilder's bottom line is this:
Those participating in the drafting and consultation process, or that plan to use GPLv3 once it is issued, should give careful consideration to whether such amendments do more harm than good by selectively overreaching for third party patent rights. There is no issue with those who choose to develop and distribute under the GPL to commit their own copyrights and patent rights in their contributions to the program they are distributing. But it is quite another for the GPL to seek to reach out and attempt to force third parties to surrender patent rights that they hold based on work and investment unrelated to development of contributions to GPL code. Particularly when the terms of the GPL are revised selectively to target specific parties, undo their perfectly legal contracts, or forge a broad agreement not to do business with such parties, this calls into question the legitimacy and enforceability of the GPL, and unwittingly may create new liabilities for its drafters and users. It also is a direct attack on the freedom of developers and companies to work together - seeking to undo or frustrate efforts to build bridges between the two worlds of open source and proprietary software.
If paragraphs 4 and 5 are retained in the final draft, those intending to use the GPLV3 should get the advice of legal counsel before doing so and possibly incurring significant liabilities.