This is a list of so-called bad sources of content that initially appear usable on Commons, but on closer inspection are not usable or are self-contradictory. Files from any of these sources should be tagged with the {{subst:nld}} ("no license") or {{subst:npd}} ("no permission") templates. Doing so will place such files in the adequate subcategory of Category:Unknown.
The images must not be provided for download (elsewhere) in the Internet. (original German: "Die Bilder dürfen nicht im Internet zum Download angeboten werden.")
The images must not be included in (other) collections of images. (German: "Die Bilder dürfen nicht in Bildersammlungen einverleibt werden.")
These are only two of more very clear hints, that this page is an unusable source.
While they claim to be licensing their images under the Creative Commons Attribution license, the page that links to it adds several more restrictions, namely,
Despite the text of the license they linked to from their page, their intent is quite clearly to allow a non-commercial, no-derivatives attribution license, which is not acceptable on the Commons. Whether linking to the CC-BY license would invalidate these stated restrictions is a finer legal point than we are qualified to deal with; furthermore, even if this would lean in our favor, it is also good form to respect the intent of copyright holders, rather than try and catch them out on legal technicalities like this.
"A community of graphic artists creating and sharing free raw image files!" - that's the slogan. The website is intended as non-commercial but they also allow for cc-by licensing. Regrettably they take their slogan's "creating" with a grain of salt. For example, Vince-Carter-Magic-PSD32033 (and all images shown as related images) are taken from elsewhere, published on other websites. The EXIF of this image states "Copyright Notice: Copyright 2009 NBAE (Photo by Fernando Medina/NBAE via Getty Images)". linksearch
Appears to consist mostly of uploads by people who do not have the authority to license the copyrights in them, or release the content into the public domain. The website also does not retain good sourcing metadata. Clause 6.1 of the Terms of Use Agreement (last reviewed on ) allows uploaders to mark their files as private or to delete them, which is declared to have the effect of terminating the license for reuse of the files by other people.
As with fotodatenbank.com, the usage conditions [2] are restrictive:
Images can be used (...) excluding collections of images or similar where PixelQuelle.de images can be dowloaded or bought. (original: (...) "Ausgeschlossen hiervon sind Bilddatenbanken, Bildkataloge oder ähnliche, bei denen PixelQuelle.de Fotos zum Download oder Verkauf angeboten werden.")
Although Seebeforeyoudie will gladly give you a free release for the images on their site, they don't actually have the right to do that. Seebeforeyoudie accepts open submissions from the Internet, and doesn't require their users to agree to any license at upload. They do not even appear to make an effort to ensure that the uploader is the copyright holder. As such any claim that they make about their images being freely licensed is inaccurate at best.
Skyscrapercity (sometimes referred to as SSC) is a forum to which users upload images (often original content, sometimes copyright violations from Flickr etc). No free licensing is required for uploads, so unless compatible licensing is explicitly declared in the forum, or the image is public domain due to age, an OTRS email from the copyright holder is required.
Images sourced from Stock.xchng (sxc.hu) are not allowed on Wikimedia Commons, unless they are explicitly licensed under a free license. Preferably those permissions are recorded in OTRS. All Stock.xchng image that have not been independently released under a free license are subject to speedy deletion since July 1, 2007. See Commons:Deletion requests/Template:Sxc-warning and Template:Sxc-warning for more information.
Although these are commonly assumed to be projects of the Federal Government of the United States, they are actually operated by government contractors and reserve copyrights on their works. Specifically, Lawrence Berkeley National Laboratory does not allow their images to be "used for commercial purposes"[3] and Lawrence Livermore National Laboratory states that "permission to reproduce may be required."[4]Other national laboratories may have different terms with may or may not be compatible with Commons licensing policy.
The site claims that you can use any of its images (which are watermarked) as long as references are made to their site.[5] It also does explicitly allow free modifications of the image, which supposedly means no one can remove their watermark. The key point is that none of the pictures hosted on World Stadiums can be determined to be free of copyright. They do not attribute the authors of the pictures. Most of their photos are copyright violations (taken from forums, official sites, scans of magazines and newspapers, etc): cropped and resized copies of copyrighted images. Others are resized versions of images licensed under Creative Commons ShareAlike, but World Stadiums do not attribute the licensors as required by the license.
• 
• 
