Whenever there is a shooting spree, they always want to take the guns away from the people who didn't do it?

Take a look at the so-called gun-show loophole. Federal law requires all licensed gun dealers to conduct background checks. The "loophole" refers to the fact that some people who attend gun shows bring personal firearms to sell. This, say gun-control advocates, provides criminals with a major source of illicit weapons, so it's important to close the gun-show loophole.

There are four problems. First, the Bureau of Justice Statistics and the National Institute for Justice have found that only 1 or 2 percent of offenders obtained their weapons from gun shows. Second, the activity at issue -- private, person-to-person firearms sales -- is not limited to gun shows, so calling it a "gun-show" loophole is disingenous.

Third, at least one proposed remedy would put all gun shows out of business. It would define as a vendor any attendee who brought a firearm to a gun show with the intent to sell it. It then would require gun-show promoters to provide to authorities the names of all "vendors" 30 days in advance of the show. That's like asking a seafood restaurant to provide in advance the name of every diner who orders crab cakes. It can't be done.

Finally, about 5,000 gun shows take place every year. Between 2,500 and 15,000 people attend each of them. The legislation aimed at the supposed loophole, therefore, would incommode millions of law-abiding people in the faint hope of producing a reduction in crime marginal at best.

Alas, that approach is not unique to gun control. It is becoming pervasive.

Witness the current approach to airport security. Instead of using behavioral profiling to finger likely terrorists, the TSA subjects everyone to invasive and degrading scanning and pat-downs. As if a 3-year-old boy with a can of Play-Doh presented the same potential menace as a perspiring young man with a glassy stare wearing a bulky coat and chanting under his breath.

Witness also the recent paroxysm of panic surrounding caffeinated alcohol drinks. After a handful of highly publicized hospitalizations in which beverages such as Four Loko were involved, several states banned them. The FDA quickly followed suit.

In a statement that ranks right up there with "the check's in the mail" for truthiness, an FDA spokesman said "we're taking a careful and thorough look at the science and the safety of these products." In fact, the FDA decision rests on only a few marginally relevant studies, including -- kid you not -- an Internet survey of college students, and another that focused exclusively not on pre-mixed beverages sold in convenience stores, but rather on cocktails made of vodka and Red Bull.

Don't imagine for a second this will reduce college students' desire or ability to mix booze and caffeine. Already, a YouTube video has surfaced showing how to make homemade Four Loko with malt liquor, caffeine tablets, energy drinks, and Jolly Roger candies. Nor does it affect other booze/caffeine concoctions, such as rum and Coke, "Jaeger bombs," or 60-proof Allen's Coffee Flavored Brandy, the top-selling liquor in Maine.

One thing the ban will do: Make it harder rather than easier for imbibers to know how much alcohol and caffeine they're ingesting. The contents of a can of Four Loko are well known: 12 percent alcohol and about 150 miligrams of caffeine. One 23.5-ounce can equals five beers and a cup of coffee. But the amount of alcohol and caffeine in a mixed drink such as vodka and Red Bull, or rum and Coke, will vary widely depending who's pouring.

As for the countless drinkers who enjoyed Four Loko, Joose, and similar beverages responsibly, too bad. They're out of luck.

Washington soon might be going after your medicine cabinet, too, thanks to the war on meth. Reason magazine's Jacob Sullum recently summarized that war this way: The government first "encouraged pseudoephedrine-based production [of methamphetamine] by banning or restricting other precursors. Appalled by all the scary, toxic, flammable meth labs that subsequently popped up around the country, it restricted access to cold and allergy remedies containing pseudoephedrine, forcing customers to ask pharmacists for them, sign a registry, and abide by quantity limits. Those restrictions, in turn, encouraged a shift to the 'shake and bake' method for producing meth, which is less complicated and does not require as much pseudoephedrine . . . ."

But -- surprise! -- people still manage to get their hands on meth. So now some public officials, including Oregon Sen. Ron Wyden, want to prohibit over-the-counter sales of products containing pseudoephedrine altogether. If you wanted to buy some Sudafed 12 Hour or Advil Cold and Sinus, you'd have to get a doctor's prescription.

Roughly 1.4 million Americans used meth last year, and a sizable share of the product comes from huge labs in Mexico. On the other hand, 15 million Americans a year use over-the-counter cold remedies containing pseudoephedrine. Wyden's goal, then, seems to be as follows: Make life even more unpleasant for 15 million cold sufferers a year in order to shift an uncertain but probably small segment of U.S. meth production from a handful of small-time shake-and-bakers to big-time Mexican drug cartels. The effect on crime would be negligible, while the inconvenience to the law-abiding would be considerable.

In other words: Wherever there is meth, Wyden wants to take cold medicine away from the people who didn't make it.

You will not be surprised to learn he also wants to close the gun-show loophole.