In defense of the 'virtual strip-search.'

If you've passed through a major American airport in the past few months, you may have been subjected to a full-body scan. The new backscatter and millimeter-wave sensing devices that have been deployed across the country check whether people hide forbidden objects under their clothes. Privacy advocates refer to them as "virtual strip-searches." But how worried should one be about these scanners? Are they truly a grave threat to individual privacy, as civil libertarians contend?

I come at this issue as a communitarian. This philosophy, about which I have written extensively, holds that our public-policy decisions must balance two core values: Our commitment to individual rights and our commitment to the common good. Neither is a priori privileged. Thus, when threatened by the lethal SARS virus, we demanded that contagious people stay home—even though this limited their freedom to assemble and travel—because the contribution to the common good was high and the intrusion limited. Yet we banned the trading of medical records because these trades constituted a severe intrusion, but had no socially redeeming merit. (For more discussion, see The New Golden Rule.) Viewed through this lens, I must say that the case against these scanners is deeply unconvincing.

The actual threat to privacy posed by these scanners has been inflated using sensationalistic imagery. In order to illustrate how intrusive this "strip-search" is, civil liberties advocates often display a rather graphic image obtained from a scanner. Yet they neglect to mention that the image is not of an airline passenger but of a TSA employee who volunteered to test the machine. (After all, if someone is willing to expose themselves, especially for a good cause, we have little reason to object.) Moreover, as you can see, the images of passengers that actually appear on TSA screens are a far cry from the one circulated by civil liberties advocates, because the scanners are equipped with two kinds of privacy filters. One conceals the genitals and the other the face. (What's more, new scanner software replaces the realistic images of the passengers who are being scanned with a cartoon of a generic, clothed body, and marks areas that should be checked further. This software is currently being tested.) Further preserving privacy, TSA staffers who view the images are in a separate room and are unaware of the identity of the passenger who is screened.

True, when we deal with millions of travelers, day in and day out, someone somewhere will cross the line. Thus, civil libertarians make much of the fact that a scanner in use in a Florida courthouse had stored over 35,000 images (although there is no evidence that anybody dispersed these images to people not authorized to review them). Yet efforts to flag such incidents should not distract us from the essential fact that these privacy violations are exceedingly rare and not necessarily damaging.

To wit, there is virtually no evidence that body scanners have actually harmed Americans. Indeed, civil liberties advocates generally do a poor job of explaining precisely what kind of harm the scanners are supposed to cause. "Libertarians may contend that the new security measures have a “chilling effect” on people beyond those directly affected. However, there is little evidence of this effect, and it is hard to explain what exactly it means in concrete terms. Do fewer people fly because of the scanners—even when dealing with short distances, where there are ready alternatives such as the Acela and rental cars?

The ACLU further asserts that the scanners amount to “a significant assault on the essential dignity of passengers” but provides no concrete evidence to this effect. On the contrary, the people whose dignity is supposedly being assaulted do not feel that way : A January 2010 CBS News poll found that roughly three out of four Americans (74 percent) think airports should use full-body x-ray scanners because “they provide a detailed check for hidden weapons and explosives and reduce the need for physical searches.” Who should we trust to judge what does or doesn't threaten a passenger's dignity? Civil liberties activists, or the passengers themselves? As the public is well aware, being unable to fly without fear of being bombed out of the sky assaults people, and not just their dignity.

Most important, civil liberties advocates also ignore the fact that people who subject themselves to body scans do it voluntarily. They are free to choose a pat-down rather than pass through the millimeter-wave machine, and even then about 70 percent of Americans say they prefer to be scanned. (The option of choosing a pat-down should not be considered unduly coercive, since random pat-downs were mandatory even before the installation of body scanners—and civil libertarians cannot seriously argue that there should be no scrutiny at all.) Even a strong libertarian should agree that if one consents to a search, especially when there is a ready alternative, there is no room for challenges. All of these facts suggest that the main libertarian criticisms against body scanners are simply not credible.

Finally, there is the core question of proportionality and context. The real issue at hand is what experience scanners provide to most people, mostof the time, how frequent exceptional violations of privacy are, and what remedies are in place. The Electronic Privacy Information Center (EPIC), in its critique of scanners, states that new security measures “present privacy and security risks to air travelers because they might create data files directly linked to the identity of air travelers. These files, if retained, could provide the basis for a database of air traveler profiles.” (Emphases mine.) The New Republic's Jeffrey Rosen argues that "the greatest privacy concern is that the images may later leak.” Other privacy advocates hold that the radiation involved may harm one’s health. Yet these concerns—almost entirely hypothetical—pale in comparison to the possibility that terrorists might bring down more airplanes, or worse.

And, in their core mission of deterring terrorists, the body scanners cannot help but work. The ACLU argues that, “It is far from clear that body scanners would have detected the ‘anatomically congruent’ explosives [Christmas Day bomber Umar Farouk Abdulmutallab] hid in his underwear.” And, it says, “some experts have said explosives can be hidden by being molded against the human body, or in folds of skin, and British newspapers are reporting that government testing in the UK found that the technology comes up short in detecting plastic, chemicals and liquids.” But this type of argument—the same type that the ACLU applies to nearly every security measure—is a bait and switch. It does not answer the question of how much security the scanners add.

Simply put, security effectiveness does not require 100 percent success, just a significant increase in the detection capability of the measures in place. In this way, the millimeter-wave devices narrow the opportunities for terrorists, add ways in which they can be detected, increase the probability that they will make an error, and reduce their confidence—as well as the confidence of those who employ them.

When all is said and done, we must vigilantly protect our rights, but we must also be concerned about our security. The spirit of this approach is embodied in the Fourth Amendment, which does not ban all searches—only unreasonable ones. And the searches that body scanners perform are reasonable, if we keep in mind the fact that terrorists are far from done, and that our nation has a vital interest in protecting not just rights but also lives.

Amitai Etzioni is a university professor at George Washington University and author of The Limits of Privacy and How Patriotic is the Patriot Act?.

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