Justice Department officials are turning to the 3D-printing industry to help stop the proliferation of tiny pieces of plastic transforming semi-automatic weapons into illegal homemade machine guns on streets across America.
Archived version: https://archive.is/FzBzV
Also, material sciences have flourished. Lots of plastics can even outperform metal in specific tasks
right, but are they making these out of plastic? the article says tiny pieces of plastic.