GPLv3 y patentes

El peligro de las patentes de software sobre el software libre, es precisamente que este deje de ser libre por que alguien patente determinados algoritmos o código presentes en él. La licencia dice:

[...] To prevent this, the GPL assures that patents cannot be used to render the program non-free.

11.Patents : You receive the Program with a covenant from each author and conveyor of the Program, and of any material, conveyed under this License, on which the Program is based, that the covenanting party will not assert (or cause others to assert) any of the party's essential patent claims in the material that the party conveyed, against you, arising from your exercise of rights under this License. If you convey a covered work, you similarly covenant to all recipients, including recipients of works based on the covered work, not to assert any of your essential patent claims in the covered work. ¶ →

If you convey a covered work, knowingly relying on a non-sublicensable patent license that is not generally available to all, you must either (1) act to shield downstream users against the possible patent infringement claims from which your license protects you, or (2) ensure that anyone can copy the Corresponding Source of the covered work, free of charge and under the terms of this License, through a publicly available network server or other readily accessible means. ¶ →

Nothing in this License shall be construed as excluding or limiting any implied license or other defenses to infringement that may otherwise be available to you under applicable patent law.

En resumen, según entiendo. si licencias un software bajo la nueva GPL v3 te comprometes a no demandar a nadie por algun supuesta patente que te pueda pertenecer. Y que si existe alguna patente conocida y aplicable, que se presta a todos los usuarios libremente y bajo los términos de la licencia GPL.. Supongoq ue es como decir: si liberas tu código en el que tienes patentes, olvídate de ellas. Y si tienes patentes que queires conservar, no podrás crear software libre con ellas.
Las patentes de software han sido ultimamente uno de los puntos en los que me parece que más activos han estado en la FSF. Y falta que hace.