Robert Scott Horning wrote:
I should note that I got into this whole mess because I was involved with a group that was trying to write a Wikibook about M.C. Escher, and I tried to point out that they couldn't reproduce the Escher artwork unless they somehow were able to obtain a license that could be used under the GFDL. The response was that the images were being used on Wikipedia, so why not Wikibooks? The Escher reproductions are claiming fair use, but I think it has gone way too far on Wikipedia, as I believe these to be merely a copyright violation.
I would observe that there is one significant difference between the two situations. It is one thing to use a couple of Escher's art works in Wikipedia to illustrate a biographical article about him; in my mind that could reasonably be viewed as fair use. The wholesale reproduction of his works in Wikibooks would probably not be. The difference is in the application in the substantiality rule of fair use law.
Of course, it doesn't help to know that some of Escher's works MAY be in the public domain, but it's not up to us to research and make that case on behalf of the uploader.
Ec