4.0/Technical protection measures

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Revision as of 22:28, 23 January 2012 by LuisVilla (talk | contribs) (Proposals for 4.0)
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This page presented an issue for consideration in the CC license suite 4.0 versioning process. The discussions have now concluded with the publication of the 4.0 licenses, and the information on this page is now kept as an archive of previous discussions. The primary forum for issues relating to the 4.0 versioning process was the CC license discuss email list. You may subscribe to contribute to any continuing post-launch discussions, such as those surrounding compatibility and license translation. The wiki has been populated with links to relevant email threads from the mailing list where applicable, and other topics for discussion were raised in the 4.0/Sandbox. See the 4.0 page for more about the process.

Since Version 1.0, the CC licenses have contained language prohibiting imposition of TPMs on CC-licensed works. The current language in CC BY-SA 3.0 4(a) and similar in 4(b) is the following:

You may not impose any effective technological measures on the Work that restrict the ability of a recipient of the Work from You to exercise the rights granted to that recipient under the terms of the License.

This has been controversial for a long time, potentially unnecessarily (and paradoxically, given anti-DRM clause meant to protect) limiting users' freedoms and complicating use of CC-licensed material in widely used platforms that have DRM built in.

One potential solution (the addition of a "parallel distribution" requirement) was extensively discussed, but rejected, for Version 3#DRM.

Since the creation of the original CC TPM language, TPMs have become more commonplace. For example:

  • All Japanese terrestrial broadcasting is protected by a TPM. As a result, CC Japan receives inquiries about use of CC-licensed materials in Japanese TV at least monthly, if not more frequently. CC Japan's answers to this question include the point that "you cannot use the image without creating adaptation, (or find a way not to impose TPM for the segment)." When the image is CC-BY-ND, it is impossible to comply with the current language and broadcast CC materials over terrestrial TV in Japan. Friends of CC have heard from an industry source that not imposing a TPM on a particular Japanese terrestrial broadcast is technically possible, but practically impossible. This conflict between the anti-TPM clause and digital TV was raised in 2008 Summit's Legal Day. At the time, the problem was expected but somewhat theoretical. Now that all terrestrial TV broadcasting became digital-only for most of Japan, it is real. Some at the time pointed out that TPM would not be sustainable so we could simply wait and the TPM would disappear. That prediction is not right so far.
  • Several popular game and media distribution platforms, such as the PlayStation, require TPMs.
  • It has been argued that the combination of iOS, iOS applications, and the App Store constitute an effective technological measure, so distribution of CC-licensed materials to iPhones and iPads may constitute a violation of the license. (Further research needs to be conducted on this point, and to confirm that this is the case.)

Proposals for 4.0

For ease of reference on discussion lists, please do not alter proposal numbers.

TPM Proposal No. 1: Drop prohibition of effective technical protection measures, add permission to circumvent, possibly using GPLv3's Sec. 3's well vetted language as closely as possible.

After several years of discussion, GPL version 3, Sec. 3 ("Protecting Users' Legal Rights From Anti-Circumvention Law") attempts to allow circumvention of TPMs that either (1) incorporate the GPL-licensed work as part of their functionality or (2) are used to restrict access to the GPL-licensed work. The actual language is as follows:

No covered work shall be deemed part of an effective technological measure ..."
When you convey a covered work, you waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected by exercising rights under this License with respect to the covered work, and you disclaim any intention to limit operation or modification of the work as a means of enforcing, against the work's users, your or third parties' legal rights to forbid circumvention of technological measures.

The GNU project offers an in-depth explanation. FSF-E has a summary of several talks on the subject by Richard Stallman and Eben Moglen, as well as drafts of earlier versions of this language here.

Because CC has historically focused on expressive works (i.e., "content") rather than functional works (i.e., software), it may make sense to ignore the portions of the GPL language that focuses on whether or not the work is used as part of a TPM. This would leave the following language (adjusted for terminology in CC 3.0):

When you Distribute a Work, You waive any legal power to forbid circumvention of technological measures to the extent such circumvention is effected by exercising rights under this License with respect to the Work.


  • This clause places no new obligations on the distributor, so compliance is easier when compared to a parallel distribution obligation or similar clause that requires a proactive step by the licensee.


  • Permitting circumvention is, in practice, not equivalent to ensuring access, because many TPMs may be difficult or illegal to circumvent. (For example, in Japan, such sales, manufacturing, and other acts related to circumvention device are a crime punishable up to 3 years in prison, etc., according to Art.120bis of Japanese copyright law).

Note that a clause of this type could be used in parallel to the existing language; i.e., the license could both prohibit application of TPM and permit circumvention if a TPM was applied.

TPM Proposal No. 2: Allow parallel distribution in place of total TPM prohibition. Pros:

  • Allow copying of a digital image under CC-BY into increasingly common TPM-protected distribution channels, such as the Japanese TV programs discussed above.


  • It was explicitly rejected during the 3.0 discussion. There were a variety of reasons for this, including negative reception by CC's affiliate teams around the world. Version_3#DRM contains extensive review of those discussions.

Please add other TPM proposals here, and number them sequentially.

Related debate

We encourage you to sign up for the license discussion mailing list, where we will be debating this and other 4.0 proposals. HQ will provide links to related email threads from the license discussion mailing list here.

Relevant references

Please add citations that ought to inform this 4.0 issue below.