“What limitations upon the right to bear arms are permissible? Some undoubtedly are, because there were some that were acknowledged at the time. For example, there was a tort called affrighting, which if you carried around a really horrible weapon just to scare people, like a head ax or something, that was I believe a misdemeanor. So yes, there are some limitations that can be imposed.”—Justice Antonin Scalia

In his 2008 DC v. Heller decision, which for the first time established gun ownership as an individual right under the Second Amendment, Justice Antonin Scalia made it very clear that this was not “a right to keep and carry any weapon whatsoever in any manner whatsoever and for whatever purpose.” He noted that many time and place regulations on gun possession were perfectly acceptable under the Constitution, and he singled out laws “prohibiting the carrying of dangerous and unusual weapons” as part of our Founding tradition.

In a later interview, Scalia doubled down on the “dangerous and unusual weapons” angle by bringing up the common-law principle of “affrighting,” or “the affray” — an ancient prohibition on carrying weapons with the intention of intimidating people or the public at large. As an early American legal commentary puts it, “it is an affray, under common law, for a man to arm himself with dangerous and unusual weapons, in such manner as will naturally cause terror to the people.”

And it is a behavior that we are starting to see with frightening regularity. Take the guy in Georgia who recently brought a gun to a little-league baseball game and waived it around at parents just to prove that he could. Or the open carry activists in San Antonio who have been going into stores and restaurants with assault rifles in order to get their point across — behavior that even the NRA has described as “downright weird.”

The NRA, of course, has a lot of good lawyers who understand that this behavior falls well within a category that Justice Scalia has declared beyond the protection of the Second Amendment. And, I suspect, the NRA does not want communities having in-depth discussions of what is now an obscure common-law principle that just happened to be accepted by the people who wrote the Second Amendment. A real understanding of “affrighting” would not be good for their legislative agenda.

The original understanding of a “dangerous and unusual weapon” could end up becoming very important for proposals to ban military-style, or “assault” weapons. One of the most common arguments against such bans is that they proscribe certain weapons based on cosmetic features alone while leaving other weapons with equal or greater functionality untouched. Under the logic of the common-law affray, however, it is only the cosmetic features that matter. A weapon need not be extremely deadly to constitute a potential crime against the public peace. It need only look extremely scary.

But for now, there is a rare agreement between the NRA and advocates of gun control legislation. We can all agree that it is wrong to carry scary-looking weapons in public for the expressed purpose of intimidating other people. One of the most conservative Supreme Court justices in history issued an engraved invitation for states and communities to make such behavior illegal. I do not believe that there are any good reasons not to take him up on it.