How could using code released under CC0 infringe on the author's patents?

Question

Creative Commons defines a CC0 license type (here's the full legal code) that claims to allow creators to release their works into the public domain by waiving "all their copyright and related rights in their works to the fullest extent allowed by law."

They claim in their FAQ (and the FSF confirms) that CC0 is compatible with the GPL, which is approved by the Open Source Initiative (OSI) for use with software. However, OSI has not approved CC0 and does not recommend its use as an OSS license (emphasis mine):

The most serious of the concerns raised had to do with the effects of clause 4(a), which reads: "No ... patent rights held by Affirmer are waived, abandoned, surrendered, licensed or otherwise affected by this document.". While many open source licenses simply do not mention patents, it is exceedingly rare for open source licenses to explicitly disclaim any conveyance of patent rights, and the Committee felt that approving such a license would set a dangerous precedent, and possibly even weaken patent infringement defenses available to users of software released under CC0.

I'm not sure I understand the basis for concern here (or why CC0 includes this clause to begin with, but that's another issue). I understand that you can't make someone else's patents available by putting code that utilizes those patents into the public domain, but the clause specifically refers to the "Affirmer's" patent rights (the person who decided to release the code in the first place).

What evidence is there to support the idea that using code released under CC0 would ever result in infringement of the author's own patents? I'm looking for a specific example to illustrate when and how this could ever be a problem.

Answer 1

Sparr's original answer was good, but he should have left in the bit about being sued.

The point is that the language used in CC0 constitutes a legal hazard for anyone that receives a program under CC0 and uses it in good faith.

This is the infamous patent clause of CC0:

No trademark or patent rights held by Affirmer are waived, abandoned, surrendered, licensed or otherwise affected by this document.

The typical scenario that will create a legal hazard for you is this:

• You work on a software project (it may be open source or ARR).
• You see some other software (typically a library) that will fit very well into your project, and you notice that it is offered under the terms of CC0.
• You incorporate said library into your project.
• Unknown to you, the library offered under the terms of CC0 contains patented code. The patent is owned by the Affirmer (the person that did the PD dedication, usually the initial author of the library).
• After some time, for instance after your project has evolved into something successful and profitable - the Affirmer surfaces with his submarine-patent and demands that you pay royalities to use the library.

At this point, this patented library may be deeply integrated in your project and stopping using it may no longer be practical.

To make sure he gets paid, the Affirmer can threaten to sue you unless you pay up. Because the CC0 dedication has the quoted sentence, you're going to have a real hard time defending yourself against the Affirmer's demands in court. In all probability, your cheapest option (at least if the Affirmer is not too greedy) is to pay the patent royalties.

If you compare the CC0 with real free software licenses, such as GPLv3, you'll find this:

Each contributor grants you a non-exclusive, worldwide, royalty-free patent license under the contributor's essential patent claims, to make, use, sell, offer for sale, import and otherwise run, modify and propagate the contents of its contributor version.

Do you spot the difference?

If somebody would try to pull the submarine-patent trick with software licensed under GPLv3, it is very unlikely that they shall prevail if they sue you, as the license is designed to make such a lawsuit fail.

The point is that, if you choose to use a badly designed legal tool, which is what CC0 is, it is much easier to intimidate you by into paying royalties, than if you stick to software that provide legal immunity against this type of lawsuits.

Answer 2

Suppose that I patent an algorithm, X. Then I develop and release an implementation of that algorithm, Y. I release Y with an open source license, granting permission for others to use and distribute Y. Generally speaking, it has always been assumed that my granting of permission to use and distribute Y has also been a grant to use and distribute X. However, CC0 makes the very unusual decision to explicitly not make that grant. So, if I release Y under CC0 and you use Y in your project, then you have violated my patent rights in X.

Answer 3

First off, to answer your main question, the Open Source Initative says that they did not reach a consensus and that Creative Commons withdrew their application.

In February 2012, Creative Commons submitted CC0 to the OSI for approval as an open source license, requesting that the OSI evaluate the public license fallback section, since the rest of the text is a waiver of rights rather than a license. An unexpectedly intense and detailed discussion followed — search for "CC0" and "Creative Commons Zero" in the subject headers of the February 2012 and March 2012 archives of the OSI License Review mailing list.

CC0 was not explicitly rejected, but the License Review Committee was unable to reach consensus that it should be approved, and Creative Commons eventually withdrew the application.

With that, it seems that there was discomfort for the affirmer to release information under this license that could possibly conflict with anything that was included. To make this more clear, it looks like possible legal conflicts due to the inclusion of something could potentially wind up disastrous for the affirmer, as it may be interpreted that the patent had been released into the public domain. I don't know of any examples, but this might be a fear.