“‘Curiouser and curiouser!’ cried Alice (she was so much surprised, that for the moment she quite forgot how to speak good English). ‘Now I’m opening out like the largest telescope that ever was! Good-by, feet!... Oh, my poor little feet, I wonder who will put on your shoes and stockings for you now, dears?’” The smart money says that it won’t be the folks from the Transportation Security Administration, who make two million travelers take their shoes off every day at airports in the U.S.

Lewis Carroll’s Alice would have had trouble distinguishing reality from Wonderland had she been with me on the Sunday after Thanksgiving as I watched a TSA officer confiscate my father’s aftershave at the airport in Burlington, Vt. It was a 3.25-ounce bottle, clearly in violation of the currently permissible three-ounce limit for liquids. Also clear was the bottle, which was obviously only about a quarter full. So even the members of some isolated human populations that have never developed sophisticated systems for counting could have determined that the total amount of liquid in the vessel was far less than the arbitrarily standardized three ounces. But the TSA guy took the aftershave, citing his responsibility to go by the volume listed on the label. (By the way, the three-ounce rule is expected to be phased out late in 2009. Why not tomorrow? Because of the 300-day-rules-change rule, which I just made up.)

Feeling curiouser, I did a gedankenexperiment: What if the bottle had been completely empty—would he have taken it then? No, I decided. When empty, the bottle becomes just some plastic in a rather mundane topological configuration. Not to mention that if you really banned everything with the potential to hold more than three ounces of liquid, you couldn’t let me have my shoes back. You also couldn’t allow me to bring my hands onboard. I kept these thoughts to myself, of course, because I wanted to fly home, not spend the rest of the day locked in a security office explaining what a gedankenexperiment was.

I first commented on what I used to call “the illusion of security” in this space in July 2003, after attending a conference on freedom and privacy. We heard the story of an airline pilot who had his nail clippers snatched away by the TSA just before boarding his plane. He then walked into a cockpit equipped with an ax. (Which is a horrible tool for cutting your nails, although, I have to admit, my dad might try. A former U.S. Marine and builder, he does his manicuring with a foot-long metal carpenter’s file and some 80-grit sandpaper. And you wonder how I got to be this way.)

It used to be that you could bring shaving cream with you when boarding a plane, but they would take away your razor. Now you can carry on a razor, and they take away your shaving cream. (They did indeed seize my dad’s shaving cream at the airport in Fort Lauderdale the Monday before Thanksgiving.)

Although the mostest curiouser thing has to be when hundreds of people docilely snake through security lines amid announcements that the “threat of a terrorist attack is high.” Compared to what? The day before, perhaps, when the real threat posed by terrorists to your life was much, much smaller than your chances of dying in the bathtub. And today the threat is only much smaller than your chances of dying in the bathtub. Here’s how you know that the terrorist threat isn’t really high: the airport is still open, and your flight hasn’t been canceled.

A much better term than “illusion of security” can be found in an article by Jeffrey Goldberg in the November 2008 issue of the Atlantic: “security theater” (www.theatlantic.com/doc/200811/airport-security). Goldberg holds that TSA agents and passengers go through performances designed to make everybody feel better, but with little effect. He talks about how he has been able to carry knives and box cutters onto planes—he even got past security with a device on his torso called a Beerbelly, a bladder that holds up to 80 ounces of liquid you can drink from through a tube.

Goldberg didn’t fill the thing up, but he did exceed the three-ounce limit by just 21 ounces. He believes that our current airport procedures may succeed in catching dumb terrorists. But the time, energy and money would be better spent on gathering intelligence if we want to catch the smart ones. And keep my dad clean-shaven.

Note: This article was originally printed with the title, "Not a Close Shave".