Commons:Enforcing license terms


Where external reusers of Commons content do not respect the specified license terms, only the copyright holder can enforce the license terms. Neither the Wikimedia Foundation nor the Commons community is in a position to seek out license violations by reusers, or to enforce license terms when violations are pointed out.

This page describes some tools for copyright holders to identify their work when they upload it on Commons (so that reuses outside Commons can be detected), and provides some guidance on dealing with reusers who violate license terms.

Clarity of license termsEdit

Most aspects of a license are clear enough from applying the relevant license template. The exception is attribution: this is not always made clear enough by uploaders. If you want reusers to credit you correctly, be sure to make the required attribution as clear as possible. One way to do this is to use the {{Credit line}} template in the |attribution field of the {{Information}} template. Alternatively, many license templates, like {{Self}} or {{Cc-by-sa-3.0}}, have |attribution parameters to specify the desired form of attribution. (If you use both, be sure not to contradict yourself!) Examples of different types of attribution can be found at Commons:Credit line.

Tools for identifying your workEdit

  • Watermarks
    • Visible watermarks   Do not add visible watermarks to your images, such as printing your name in the corner. These will be removed as they affect image quality.
    • Invisible watermarks   (aka digital watermarking). Invisible watermarks identify the author and license without visibly damaging image quality and are designed to be difficult to remove. The most popular provider is Digimarc, but more affordable competitors like SignMyImage[dead link] exist. Most digital watermarking services offer a subscription to a search engine that tracks uses of your images throughout the web.
  • EXIF   Add EXIF metadata to your image describing the author and license. Many cameras and image processing software can be configured to do this automatically, and it will remain with the image when it is downloaded and copied. Although EXIF data is easily removed by third parties, most do not do so, allowing you to prove that the image belongs to you and demand compliance.
  • File description page   - the file description page gives you scope to clarify attribution and sourcing. You can, for example, if you have a Flickr account or other website where you have uploaded the image, add that as a source in the "Source" field of the {{Information}} template.
  • Image searches   Google's Search by Image provides a free option for finding uses of your image throughout the web. However, unlike digital watermarking it does not prove that the images belong to you and may sometimes produce unpredictable or incomplete results.

What to do when you find a violationEdit

 See also: Wikidata:Q4994074.

Some general advice on how the copyright holder can enforce license terms on third parties:

  • If you identify a non-compliant use of your image, send a request to the user who posted it asking to comply with the license or cease using the image. Many will be happy to do so.
    • A common violation of license terms is failing to provide proper attribution; the template {{License enforcement request}} is available to help Commons content contributors draft a letter to a reuser to ask them to provide proper attribution.
  • For those who refuse to comply, you can follow up with a legal notice requiring the copyright violation to be removed. Details of how to do this vary by country; you might well need to obtain legal advice. In the United States, the Digital Millennium Copyright Act (DMCA) provides for "takedown notices" which are relatively easy to issue (see e.g. this article for an introduction). Notices can be issued to the website hosting the image and/or their ISP.
    • If they still refuse to comply, you have the option to seek representation and sue them.
  • Consider creating a "hall of shame" of noncompliant users by listing them on your website and/or on the file description page's talk page. This might damage their reputation and encourage compliance.

Tracking correct reusesEdit