3d Printing presents compelling challenges in legal compliance terms. I have spent time today working with a company in central London discussing security issues concerning this new technology. What designs can be uploaded on the web? How can the way the designs are printed be regulated? What terms and conditions should the user agreement incorporate? Will this technology be a flash in the pan or hardware that we will see in all our homes in ten years time? How do you differentiate between someone who wants to print out a part for a computer or other innocent purposes and someone who wants to print out something a little more concerning?