Jim Harper’s post Monday, responding to communitarian Amitai Etzioni on “strip search” scanners at airports, gives me an opportunity to mount one of my hobbyhorses.

My beef with Etzioni’s conclusory argument isn’t just that, as Jim observes, he purports to “weigh” the individual right to privacy against the common good (here in the guise of “security”) without any real analysis of the magnitudes on both sides. It’s that his framing is fundamentally backwards. The importance of privacy is, to a great extent, a function of its collective dimension—a point to which you’d think a communitarian theorist who’s written an entire book on privacy would be more keenly attuned. If I may indulge in a little self-quotation:

[W]hen we talk about our First Amendment right to free speech, we understand it has a certain dual character: That there’s an individual right grounded in the equal dignity of free citizens that’s violated whenever I’m prohibited from expressing my views. But also a common or collective good that is an important structural precondition of democracy. As a citizen subject to democratic laws, I have a vested interest in the freedom of political discourse whether or not I personally want to [engage in]–or even listen to–controversial speech. Looking at the incredible scope of documented intelligence abuses from the ’60s and ’70s, we can add that I have an interest in knowing whether government officials are trying to silence or intimidate inconvenient journalists, activists, or even legislators. Censorship and arrest are blunt tactics I can see and protest; blackmail or a calculated leak that brings public disgrace are not so obvious. As legal scholar Bill Stuntz has argued, the Founders understood the structural value of the Fourth Amendment as a complement to the First, because it is very hard to make it a crime to pray the wrong way or to discuss radical politics if the police can’t arbitrarily see what people are doing or writing in their homes.

I’m actually somewhat sympathetic to the notion that the individual harms that result from strip scanners are relatively slight, especially when passengers can opt for a pat down instead. In the worst case scenario, some unscrupulous TSA employee might find a way to save and circulate some of these blurry quasi-nude images, the embarrassment potential of which is likely to be mitigated by the fact that the x-ray view doesn’t really show an identifiable face.

I’m much more concerned about the social effect of making such machines commonplace—of creating a general norm that people who wish to engage in routine travel must expect to expose themselves in this way. As Michel Foucault famously observed, surveillance is not merely the passive gathering of information; it exerts a “disciplinary” power, creating what he called “docile bodies.” The airport becomes a schoolhouse whose lesson is that not even the most intimate spaces escape the gaze of authority.

In his fine book The Naked Crowd, legal scholar Jeff Rosen recounts presenting his students and other audiences with a hypothetical choice between going through a strip scanner and a “Blob Machine”—a similar scanner programmed to filter out the passenger’s body image and project any foreign objects (as determined by density) on a generic wireframe mannequin. Though he assured them that the Blob Machine was just as accurate at detecting hidden objects, he found that in every group some significant number of people still preferred to subject themselves to the strip-scanner, in what Rosen calls “a ritualistic demonstration of their own purity and trustworthiness.” But there may be more to it than that. To expose oneself, render oneself vulnerable, is also closely linked to rituals of subordination—not just in human cultures, but in the animal kingdom. Think of the pack dog signaling his recognition of the alpha male’s (or owner’s) dominance by rolling over to expose his belly. In the context of pervasive fear of terrorism, this kind of routine exposure is a way of reassuring ourselves of the power of our protectors, quite apart from whatever immediate utility the strip-scanners have as a detection and deterrence mechanism. We ought to be a little wary of any “security” measures that seem to feed into that psychological mechanism.

While I don’t think these sorts of considerations ought to be dispositive by themselves in particular circumstances where a security measure is otherwise justifiable in more conventional cost-benefit terms, I think a communitarian commentator in particular ought to be a lot more sensitive to the cumulative cultural effect of many such measures. Formal institutions and rules are important to the preservation of free societies, but so are background norms and expectations. A society that comes to accept as normal the routine observation of our naked bodies by authority as an incident to travel is, I think, in danger of losing some important cultural capital.