Invent something and the first thing that goes through some people's minds -- especially politicians' minds -- is what might go wrong.
3D printers now allow you to mold objects right in your living room, using patterns you find online. It's a revolutionary invention that will save time, reduce shipping costs and be kind to the earth.
But what critics see is: guns! People will print guns at home! Well, sure.
On TV, Rachel Maddow sneered about "a well-armed anarchist utopia, where everybody fends for themselves with stupid-looking plastic guns. ... It's a political effort to try to do away with government."
Do away with government? If only we could do away with some! Big-government politicians and their cheerleaders in the media focus on threats posed by innovation because they fear loss of control. They move to ban things.
In Texas, Cody Wilson used a 3D printer to make a plastic gun. He called it "the Liberator" and posted its specs on the Internet. The State Department then ordered him to take the specs down. He did. But by then, 100,000 people had downloaded it.
Wilson takes pride in pointing out how his gun shows that gun "control" is an illusion. Being able to print a gun in your own home will render laws against purchasing guns unenforceable and irrelevant.
"I'm your full-service provocateur," Wilson told Kennedy, my TV show's correspondent. "Here's the printed gun. I'm not here to make you feel better about it. I'm here to say, 'Look, this space is occupied. Deal with it.'"
The "Liberator" didn't work well. It broke before Kennedy could fire a shot. However, printed guns will improve over time. Wilson's point: "prohibiting this is no longer effective."
Technological innovation constantly threatens centralized authorities.
Now we take the Internet for granted, but when it first became popular, people worried that it would mainly be used by terrorists, child molesters and money-launderers.
"Smash the Internet!" said a cover story in the conservative magazine Weekly Standard, illustrated with a sledgehammer smashing a computer screen.
Even today, after Google, Facebook, Wikipedia, eBay, Yelp, Craigslist, WebMD, YouTube and more have clearly made our lives better, Luddites in the media fret about problems.
"The Internet Is Making Kids Stupid" says PC Magazine. CBS's Bob Schieffer whines that in the absence of supervising editors, "ignorance travels as rapidly as great ideas."
There's some truth behind these complaints. The Internet does make some people isolated. It does allow ignorant ideas to spread. But so what? It also creates new forms of human interaction and allows the crowd of users to correct ignorant mistakes.