Anonymous Coward writes "The DMCA notice in question isn't from some large company but over the Penrose Triangle, something that by all rights should be ancient (public domain) history.
However, because Dr. Ulrich Schwanitz was already selling a Penrose Triangle on Shapeways, he felt justified in issuing a takedown notice from outside the US at Thingiverse, a site dedicated to sharing 3D models of 3D printable objects.
While the claim is almost certainly spurious due to the ancient nature of the original triangle, the fact that the poster generated his version from scratch, and the fact that copyright does not protect ideas, the DMCA requires that such claims be responded to swiftly, so the Thingiverse moderators have removed the offending object.
This is a pretty clear cut example of the chilling effect of what essentially amounts to the guilty-until-proven-innocent model of the DMCA rules on hosting material of questionable copyright."
Link to Original Source