<i>Copyright provides a helpful contrast. Digital files themselves infringe. They are copies of the work.</i><p>Is this true? I&#x27;m skeptical. I own hundreds of MP3s legitimately bought from amazon.com without any DRM on them. The existence of these files on my computer are in no way evidence of any infringement. Only if I were to share these files online without first securing the right to do so do I infringe. It is the act, not the file that is illegal.<p>Luckily, they seem to get this distinction in the following statements:<p><i>We argue that if someone sells a CAD file that prints a patented item, that should be considered infringing... But what if someone is not selling the CAD file? Instead, they just possess it. Should that be infringement, too? We think not. The patent system encourages others to design around existing patents, which is often done in a virtual space. If the CAD file itself would be viewed as infringement, then the system could lose such beneficial improvement efforts.</i><p>First a quibble: very few 3D-printing enthusiasts use CAD, they use STL files or GCode (the actual code instructions for the printer). The fact that the author makes no mention of this tells me they haven&#x27;t really taken the time to understand the technology they are critiquing.<p>Secondly, they are painting an incomplete picture here. You are either selling patented 3D files, which should be illegal, or you are working with them personally, which should remain legal in the spirit of promoting innovation. But what about collaboration, which requires sharing these files? 3D Printing Designers often share their designs in order to solicit feedback. What happens if I send my design to a someone on 3DHubs to have them print it for me?<p>Thirdly, how the heck are designers supposed to know what is patented and what isn&#x27;t? Have you ever tried to find prior-work on the US Patent Office web site? Good luck getting the keywords right or sifting through the PDF drawings to see if someone else had your idea. This isn&#x27;t at all like copyright infringement, where you are copying something someone else created. In a world of obvious ideas, inventing the same thing as someone else is very easy.<p>I agree with the other comments that predict this is the beginning of a very ugly lobbying effort, and the only ones who are going to get rich off it are the lawyers.