Public Knowledge's Michael Weinberg, who wrote "It Will Be Awesome if They Don't Screw it Up: 3D Printing, Intellectual Property, and the Fight Over the Next Great Disruptive Technology", a fantastic 2010 white-paper on copyright and 3D printing, has penned a followup.
He sez, "As a follow up to It Will Be Awesome if They Don't Screw it Up, What's the Deal with Copyright and 3D Printing? takes a deeper dive into the relationship between copyright and 3D printing. After more than a decade of being trained that every digital thing is protected by copyright, 3D printing gives us an opportunity to step away from our computers and remember that most of the things in the world are not protected by copyright. That means that they are freely available to be build upon, remixed, and improved without permission. With this paper we are trying to make sure people understand what is, and what isn't, protected by copyright so they can build more cool things."