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Many Americans – including law enforcement officers – were expressing fear Tuesday over the thought of guns being churned out by 3D printers on demand. That’s understandable. The thought of criminals, terrorists and mentally ill people pressing a button and getting rifles and pistols popping out of printers like candy out of a vending machine is frightening.

But that idea is also fundamentally mistaken.

Under a settlement reached in June between the State Department and a company called Defense Distributed, it was supposed to become legal Wednesday for the company to make blueprints for hard-plastic guns available for download on the Internet.

But with only hours to go, a federal judge in Seattle issued a temporary restraining order Tuesday blocking the settlement from taking effect at least until an Aug. 10 hearing. The order came in response to a lawsuit by eight Democratic state attorneys general, who argued that 3D-printed guns posed a risk to public safety.

There’s a lot of misinformation floating around about exactly what 3D printing of guns is and what it’s not, so let’s get some facts straight about a pretty new technology.

For starters, it’s important to understand the Justice Department settled the lawsuit with Defense Distributed because the government was certain to lose.

Prior to the settlement, the government position was that sharing printing files known as CADs violated International Traffic in Arms (ITAR) regulations and thus could be censored by the government.

But Defense Distributed – which pioneered using 3D-printing technology to make guns at home  and eventually at stores like Kinko's – contended that sharing information about how to make guns on the Internet was no different that sharing it in a book or instruction manual.

The information-sharing amounts to speech, and is therefore protected by the First Amendment to the Constitution, the company argued.

The First Amendment protects speech that is unpopular as well as popular. So the argument that the amendment protects information about how to build a gun is valid.

Next, you need to know that 3D-printing technology is years – perhaps decades – away from being cheap, efficient and ubiquitous enough that it will be a major source of guns.

Currently, it takes days and a lot of money to print 3D guns – and that's not going to change for a long time.

More importantly, we know for a fact that having more guns in circulation and the legal right to carry them hasn't led to increases in gun crime and violence, even when counting mass shootings.

Yet here's Paul Penzone, sheriff of Maricopa County, Arizona, which he says is "the fourth-largest and fastest-growing county in America. Penzone says, conjuring up fantasies, that "anyone with an Internet connection and a 3D printer – readily available in stores and online – will be able to make an untraceable handgun, rifle or assault weapon with just a few clicks."

Penzone further warns in The Washington Post that "drug cartels, arms traffickers and terrorists will be able to increase their revenue and the volume of weaponry at the expense of our safety through an untraceable and unlimited method of firearms manufacturing and distribution."

We need to understand as well that criminals and terrorists already have easy access to a virtually endless supply of whatever weaponry they want.

In fact, it's perfectly legal already to build an off-the-books gun at home with parts you can order off the Internet and put together in a few hours. Given their outlaw status, drug dealers, terrorists, and gangsters are not particularly concerned whether the guns they use are traceable or not.

As anyone who has wasted hours standing in TSA lines at airports knows, terrorists aren't stopped by sweeping up babies, grandmothers and everyone else in pointless exercises in security-theater – or in secret, illegal total surveillance programs.

Terrorists are confounded by old-fashioned, dogged police work and push-back by people on planes.

If we want to minimize violence associated with drug trafficking, the smartest move we can make is to legalize drugs – something that both Canada and Mexico recognize.

Our neighbor to the north has already legalized marijuana, the only currently illegal drug that is used by more than 1 percent of Americans on a monthly basis. According to the latest National Survey on Drug Use and Health (table A.7B), 8.9 percent of us smoked weed in the past 30 days (that figure includes people in states where it's legal).

The next closest illegal substance was cocaine, which 0.7 percent of us admitted using regularly. Misuse of legal prescription drugs came in at 2.4 percent in the past month.

Mexico's new president is pushing for the same sort of marijuana reform that Canada has implemented.

We know from our own misbegotten history with alcohol prohibition that banning substances that adults want to consume creates black markets that are enforced through violence rather than contracts, courts and voluntary exchange. Attempts in recent years to intensify Mexico's war on drugs has only lead, predictably, to more, not less, violence.

What’s the next-best move to reduce gun violence and gangsterism? Put more guns into circulation and let people carry them in more circumstances.

That's what has happened over the past two decades in the United States and it correlates with a historic decline in violent crime and homicide.

According to government data, since 1996 the number of firearms in America has nearly doubled, to 393 million guns. Over the same time period, it became easier to get concealed-carry permits to walk around armed.

And yet, "from 1993 to 2015, the rate of violent crime declined from 79.8 to 18.6 victimizations per 1,000 persons age 12 or older," according to the Bureau of Justice Statistics, which published a comprehensive report last October.

Over the same period, rates for crimes using guns dropped from 7.3 per 100,000 people to 1.1 per 100,000 people. The homicide rate is down from 7.4 to 4.9 per 100,000 people.

It's impossible to know whether the increase in guns caused the decrease in violence, but we do know for sure that it didn't spark a “Mad Max”-style free-for-all either. There is no reason to think that would change if and when 3D-printing allows us all to become our own gunsmiths in our home offices.