法律/CC BY-SA许可协议与社交媒体

This page is a translated version of the page Legal/CC BY-SA licenses and social media and the translation is 16% complete.
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This article details appropriate use and attribution requirements for sharing CC-licensed materials from Wikimedia projects on social media.

When sharing content to social media, one should first distinguish whether they are the creator of the work being shared or not.

The creator has broad rights to share in any manner and to relicense the work with or without attribution or a free culture license.

If one is not the creator, the questions are how, given the means and medium of sharing, the required attribution from the CC license can be provided and whether there are any restrictions directly prohibiting sharing of content under certain licenses. In general, if good attribution is provided in a way that will accompany a work, such as in the same post or through embedding from another site, the reuse does not violate a license such as CC BY-SA.

CC BY-SA内容如何与社交媒体相互工作

The Creative Commons Attribution-ShareAlike license (CC BY-SA) and anything licensed under copyright can be broken down into two categories: Works you have produced and licensed yourself, and works that someone else (a third party) produced and licensed for you to use.

您自己创作的作品

This is the easiest category. For works such as photographs or short text that have a single author, that author can use the work however they please under copyright law. This means they may license it for use on Wikipedia, then post it elsewhere with or without attribution or under any other license as they please. In particular, licensing a work under any Creative Commons license does not prevent the author from relicensing to others under different terms.

第三方创作的作品

When posting something made by a third party to social media, there are two primary considerations to keep in mind. First, is it possible to comply with the terms of the license when posting? Second, are there other considerations or limitations that might prevent sharing certain licensed content?

For the first, there are a few ways to comply with a CC BY-SA license. The standard practice for attribution is to provide the author, license, and source. Section 4(c) (of BY-SA 3.0) allows for attribution under the licenses to be provided as appropriate to the means or medium where the work is being reused. In the case of most social media, the typical way to provide attribution would be to provide the attribution information as part of the same post where the image is shared, ideally with a link back to the source. For example, in a Facebook post, including the attribution directly before or after a CC licensed image is used would cause it to appear when the post is shared or embedded elsewhere. The attribution should provide author and the license itself (e.g., [Author Name] CC BY-SA 3.0]) and, where practical, a link back to the source for original work. If the source includes all the relevant information, such as a Commons image page, that typically satisfies all requirements.

While this post refers to the 3.0 license version (as it is one of the more common in use and covers both images and text from Wikipedia), similar language is present in both earlier and later versions, such that this type of attribution will suffice in any normal situation.

It is also possible to watermark an image with its attribution as a derivative work. This ensures that the attribution information will not be lost even if the image is extracted or directly linked from a post. This is generally discouraged (see Commons:Watermarks and CreativeCommons' page), however, as watermarks can detract from the aesthetics of the original. If one is in a situation where an image is expected to be extracted and linked separately, watermarking may provide a simple way to nevertheless retain the attribution as required by the license.

It is also worth noting that rich embedding, in which a link posted to social media displays an image and short blurb from the originating website, typically complies with the attribution required by a CC BY-SA license of any version. Since the image and the link are functionally inseparable in this kind of post, the attribution information from the original website automatically accompanies the social media posting regardless of how the link is reshared.

Some examples of effective sharing on social media are:

  • Link (from Creative Commons showing attribution in a Facebook post)
  • Link (showing an embedded medium article with a CC licensed image displaying on Twitter)
  • Link (Good attribution without a link-back from Wiki Loves Monuments Twitter. Note the gray text included bottom left as part of the image so the attribution travels with it).
  • Link (History website with Wiki Loves Monuments photo and photo credit information watermarked at the base of the image. Note that the link back to the Commons page, which includes all relevant information, meets the attribution requirement)

Some examples of not doing things right:

  • Link (A winning image from Wiki Loves Monuments linked on Reddit with an incorrect URL and no other information. No information and no link (or a wrong link) fails to meet attribution requirements)
  • Link 1, Link 2, Link 3 (All of these use a freely licensed image without crediting the author, license, or source URL. Credits like "from Wikimedia Commons" or "from Wikipedia" are not usually sufficient without a link.)

Creative Commons has posted a blog entry discussing the topic with some attribution recommendations.

For the second, other considerations may include the Terms of Use or Policies of different sites. For example, Wikimedia Commons policy does not allow works to be uploaded under non-commercial or no-derivative licenses because those licenses do not qualify a work as a free culture work.

Does it violate the CC license to upload third-party material to social media?

No, it does not violate the CC license.

A social media website's Terms of Service do not override a license or the requirements of copyright law. Some users have expressed concern with a clause found in Facebook and Twitter's Terms of Service that give these platforms a broad license to use your content when you upload it. However, if you are not the author of this work, you cannot grant permissions that you do not yourself have. While this situation creates an ambiguity for users, it does not change or conflict with the copyright license of the works in question.

It should be noted that there has been past guidance that the terms of some social media websites such as Facebook or Twitter conflict with CC license conditions. However, we want to clarify that this characterization is not accurate. Social media has become a ubiquitous and important way to share works that are part of the commons so that others may have access to them and be able to reuse them. Where a user provides attribution for a work and complies with the other terms, it is then up to other reusers of the work to ensure that they comply with the license conditions and attribution provided with the work regardless of what the site's terms of use may say.

Final remark

We also note, as a final point, that we would encourage social media companies, and others who accept uploads, to explicitly address freely licensed works in their terms of use and in upload technology. Offering users a clear way to upload freely licensed works with good metadata and clarity on their usage ensures that the commons will be as widely available for as many people as possible. As an example, in 2016, Medium updated their Terms of Use to explicitly support the Creative Commons licenses (this has unfortunately been more recently removed, but we still encourage companies to consider terms like this example). Other platforms would better support free content if they add similarly clear language.