Reprinted from the St. Louis Post-Dispatch on Dec. 3.

The bumper stickers and lawn signs that quip, “This property protected by Smith & Wesson” can be a macho declaration of support for Second Amendment rights. But if the owners think they’re somehow deterring criminals, they need to think again. Such warnings actually serve as advertisements that guns are inside for the taking, and thieves act accordingly.

According to one study, as many as 380,000 weapons are lost or stolen each year nationwide because owners fail to secure them. FBI statistics suggest more than 100,000 of those thefts go unreported to police.

Instead of making themselves safer by owning guns, careless gun owners are making American homes and streets much more dangerous. They are arming criminals and evading responsibility for their own carelessness. And the National Rifle Association is complicit.

The news media organization The Trace reported in Sunday’s Post-Dispatch that reporters had identified more than 23,000 firearms recovered by law enforcers around the country since 2010. An analysis of crime reports shows the weapons were used in more than 1,500 violent crimes, including murder, kidnappings, armed robberies and sexual assaults.

The use of guns in violent crimes is nothing new. What bears deeper scrutiny is the utter laxity with which many gun owners treat these killing machines. They leave them exposed in cars, unsecured. They leave them on coffee tables or hide them in predictable places that experienced burglars can locate quickly.

Far too many don’t keep their weapons locked in gun safes, so they’re easy pickings for criminals or, worse, they’re available for children to find and play with, leading to tragic outcomes.

The Trace identified 843 firearms reported stolen in St. Louis in 2015 — nearly double the number of reported thefts in 2006.

“We have a society that has become so gun-centric that the guns people buy for themselves get stolen, go into circulation and make them less safe,” said Sam Dotson, a former St. Louis police chief.

Only 11 states require gun owners to report lost or stolen weapons. In states that don’t, law enforcers face ridiculous hurdles trying to trace stolen weapons used in crimes. South Carolina officers in 2015 seized about 3,800 firearms from a man known to purchase and warehouse stolen weapons. But prosecutors couldn’t obtain the information required to fully punish the purchaser for trafficking stolen weapons because South Carolina doesn’t have a reporting law.

Nor does Missouri. A state legislator tried to push through a reporting bill in 2014, but the NRA intervened to block it.

Gun owners’ recklessness endangers everyone, including other gun owners. The NRA might call it the price of freedom or some other silly slogan. But there is no freedom when stolen guns put the rest of us at risk. Call it the cost of carelessness.