The nation's founders didn't have guns made on a 3-D printer in mind when they drafted the Second Amendment's right to bear arms.

Fast forward a couple of centuries. Those who believe the Second Amendment confers a right to own any weapon imaginable have the upper hand with lawmakers beaten into submission by the gun industry and its sidekick, the National Rifle Association. Now a new technology could rattle profit-seeking gun makers while threatening more violence to society.

Cody Wilson, a law student in Texas, recently test-fired a gun made mostly from plastic and produced on a three-dimensional printer. In a widely seen video, the 25-year-old libertarian showed that it could work. Although only one of the gun's 16 pieces was metal, an all-plastic model would be invaluable to anyone who wants to elude a metal detector on the way to committing murder and mayhem.

Mr. Wilson was able to fire several shots before his weapon broke down under the heat, but he vows to perfect the process. He posted the blueprints for making the gun online, but the State Department ordered him to take them down. The plans have been downloaded more than 100,000 times.

Americans who don't want to see their country slip into the anarchy of undetectable guns made at home should be very concerned. Sen. Charles Schumer, D-N.Y., is and said the nation must ban printable weapons.

"A terrorist, someone who's mentally ill, a spousal abuser, a felon can essentially open a gun factory in their garage," Mr. Schumer said.

Unregulated access to plastic guns printed at home just might do what gun control advocates could not -- put a crimp in gun makers' profits. Unfortunately, it would come at the price of untold American lives due to guns that turn up in the wrong hands.