Readymake: Duchamp Chess Set
A repository for Duchamp Chess Set STL files Original link (broken): http://www.thingiverse.com/thing:305639/#files
A project by Bryan Cera and Scott Kildall.
They both have talked about it on their blog (although the posts have been deleted)
http://bryancera.blogspot.be/2014/04/resurrecting-dead-objects.html
http://kildall.com/blog/?p=1999
Some others still mention it. Plus, it hit major news websites.
Some of these files were found on : http://www.wamungo.com/PrintModel/Detail/Readymake-Duchamp-Chess-Set-53557f118970281228490c38
An July 20 snapshot of the original Thingiverse page includes a Creative Commons - Attribution - Non-Commercial - Share Alike 3.0 license.