3D printing is an old technology which emerged in the 1980s (that's ancient in tech years!). As opposed to CNC machining which takes a large object and whittles it down to the desired design, 3D printers creates an object by building outwards, layers upon layers. The design for the object is created digitally through a program such as CAD and sent off to the printer to print the object in a plastic resin. 3D printers have been used to create aerospace and medical parts and products, candy, even copies of fossils. A simple Google search will reveal the millions of things a 3D printer can produce. (This is why I love IP law, I am exposed to some really amazing and cutting edge innovations.)
Of course with it's vast capabilities of copying and printing basically anything, comes copyright and patent issues associated with 3D printers.
This technology has been around for quite some time but recently there has been an explosion of interest in 3D printing in the IP field of law. The main reason 3D printing has been a focus of IP law is because printers are now cheap and easily accessible to the average person. One can easily purchase a 3D printer for around $1,000 and have it up and running on their tabletop in their home. As a creative artsy person I would love to have one and use it to let out some of my creative energy, the possibilities are really endless. But, as with anything there are those that use it for good and those that use it for bad, and those that think they are using it for good but are really infringing on somebody's patent or copyright (think- your 12 year old self flagrantly downloading thousands of free songs on Napster, committing federal offenses left and right)
3D objects are copyrightable the same way music, pictures, and sculpture are. With a 3D printer you can easily scan any object and have the printer print it in 3D.... you all can see where this is heading right? The at-home 3D printer user can easily make an exact replica of a Mickey Mouse action figure or a 3D Olaf, acts that clearly infringe on Disney's copyrights. Patents are infringed in the same way. Also reminiscent of Napster is the widespread sharing of these files that instruct the printer to create these infringing works. DACA (The Digital Millennium Copyright Act) allows copyright holders to send takedown notices to the sites hosting the infringing files. Most of the time the sites have been cooperating and taking down the infringing 3D printing files.
All in all the 3D printer is a great technology that is used to create many useful and awesome things. And I will leave you with a little tip for when you are using a 3D printer: don't print anything that is copyrighted or patented, without consulting with your trusted IP law attorney.