By Jay Stanley, Public Education Director, ACLU Technology & Liberty Program

Okay, so no one is explicitly calling for body cavity searches for all airline travelers — yet. But the logic of those pushing for body scanners for all airline passengers, and criticizing the ACLU for opposing that, leads to the inescapable conclusion that these critics would support such a policy.

Consider:

  1. When Richard Reid brought explosives onto an airliner hidden in his shoes, the authorities made everyone remove their shoes. When security experts and other critics pointed out that this was "silly security," defenders argued that we must put up with it in order to block that particular kind of plot.
  2. Now that a disturbed person has brought explosives onto an airliner in his underwear, panicked voices want the TSA to essentially view naked pictures of every passenger who boards an airline — that’s up to 2.5 million people per day on domestic flights alone. When the ACLU and members of Congress object, critics cry that we must abandon our personal dignity and privacy in order to block that particular kind of plot.
  3. It is far from clear that body scanners will, as so many people seem to be assuming, detect explosives concealed the way that Umar Farouk Abdulmutallab concealed them. Some experts have said plastic explosives can be concealed against the human body. It’s not clear how good scanner operators would have been at detecting the "anatomically congruent" explosives Abdulmutallab hid in his underwear (let alone how consistently effective bored operators would be if these $200,000 machines were placed at every screening station in every airport for 2.5 million people a day).
  4. However, if terrorists even perceive that scanners will work, they take the next logical step and conceal explosives in their body cavities. Al Qaeda has already used this technique; in September a suicide bomber stowed a full pound of high explosives and a detonator inside his rectum, and attempted to assassinate a Saudi prince by blowing himself up. (The prince survived.)

So it seems that when the next terrorist tries to blow up an airliner using this technique, all the usual jittery voices surely will once again say that we must abandon our personal dignity and privacy in order to block that particular kind of plot. So we’d just like to get ahead of the game and state right now that the ACLU will be opposed to that.

Of course, even if body cavity searches for all were made policy, terrorists would probably shift their efforts to just hiding explosives in their carryon baggage, and the TSA’s level of success in catching contraband has always been, shall we say, mixed. And reliably catching every possible means of hiding 50 grams of explosives is probably impossible given the millions of people who fly each day.

Yes, the government must zealously work to make us as safe as possible and to take every reasonable step to make sure security breaches like the ones that led to the Christmas Day attempted attack are not repeated. But we need to act wisely. That means not trading away our privacy for ineffective policies. We should be investing in developing technologies such as trace portal detectors (a.k.a. "puffer machines") that provide a layer of security without invading privacy, and in developing competent law enforcement and intelligence agencies that will stop terrorists before they show up at the airport.

Ultimately, it is up to the American people to figure out just how much privacy they want to abandon to block a few particular means of carrying out terrorist attacks. The ACLU represents those who value privacy in this debate. But when Americans make that decision, they should do so with their eyes wide open, without any illusions that this will prevent all attacks on airliners, much less attacks on shopping malls or all the infinite number of other plots and targets that terrorists could come up with if they are not stopped by competent law enforcement and intelligence agencies.

(Cross-posted to Daily Kos.)