Controversy about the Transportation Security Administration’s new screening technologies and procedures continues to intensify. The White House is reacting defensively. The chairman of the Senate homeland security committee, Sen. Joseph Lieberman (I-CT) is defending the new procedures. Opponents of advanced imaging technology have attempted to organize a nationwide “Opt-Out” yesterday, the busiest airline travel day of the year.
Travelers electing to opt-out face mandatory, invasive pat-downs. Should the number of opt-outers be substantial, the queue for invasive pat-downs could stretch TSA resources beyond their capacity. This is the result organizers intend. They hope to persuade TSA to relent on its one-size-fits-all approach to airport security. TSA Administrator John Pistole first said he would not budge and criticized proponents of the opt-out campaign for causing massive delays and missed flights, then appeared to give ground after his position was undermined by Secretary of State Clinton and President Obama. According to Pistole, the new, invasive pat-down procedure is needed to prevent threats such as the so-called Christmas Day bombing attempt 11 months ago. (The implied 11-month delay in TSA’s response is not explained.)
Pistole displays a tone of bureaucratic defensiveness that suggests he’s primarily concerned with how he would be treated in the event that an aircraft is successfully targeted by a terrorist:
“I would hate to think what happens if the government caves in on this and relaxes these procedures and someone manages to get on board a plane and causes harm,” Pistole said Monday in an interview on NBC’s “TODAY” show. “Imagine what you will be asked.”
A closer look suggests suggests that TSA’s screening procedures are illogical even if Pistole’s position is taken at face value. This reinforces the hypothesis we previously suggested, but considered very unlikely, that the reason TSA is forcing invasive pat-downs is to overcome travelers’ objections to advanced imaging. If travelers object strenuously enough to invasive pat-downs, they will begin to prefer advanced imaging technology as the lesser of two evils. This is a sensible strategy if TSA intends to replace all metal detectors with advanced imaging devices but recognizes that travelers will agree to it only if they have no other option.
Meanwhile, opponents of the invasive pat-down have few options. As we reported previously, TSA mandates the invasive pat-down under two circumstances: (1) the traveler sets off the metal detector, indicating the potential presence of a metal weapon, or (2) the traveler refuses to submit to an advanced imaging scan, which is said by TSA to be capable of detecting both metal and non-metal objects that may pose a threat to safe air travel. John Tyner’s now-famous experience indicates that TSA is no longer allowing travelers to choose which technology to endure.
The chart below illustrates TSA’s current airport screening security system as an event tree. There are six events, the last event being the only significant one from a security perspective — the interception of a non-metallic weapon.
Events #1 and #2
Airports have two technologies: conventional metal detectors (low emission x-rays) and advanced imaging machines (millimeter wave or backscatter x-rays). Casual empiricism from frequent air travel indicates that travelers generally can choose which technology to submit to by choosing the lane with the desired screening device.
Tyner’s story suggests that TSA now exercises the authority to override travelers’ preference for the metal detector. This is the initiating event that created the Tyner controversy because Tyner had voluntarily submitted to the metal detector, apparently several times. It also is the initiating event in the wider controversy over advanced imaging. TSA says passengers can refuse, but if they do the consequence is a mandatory invasive pat-down. There would be no organized campaign to opt-out if TSA allowed those who refused enhanced imaging to be screened by the metal detector instead.
Each screening technology yields both “negatives” and “positives”. A “negative” means the technology detected nothing about the traveler consistent with a threat to safety, allowing the traveler to proceed. A “positive” means the technology detected something consistent with a potential threat, thus triggering more intensive scrutiny.
Historically, a positive ping from the metal detector would lead to enhanced screening by electronic wand and perhaps a limited pat-down. This limited pat-down generated no controversy. TSA has replaced the limited pat-down with the invasive one now widely referred to as groping. In Tyner’s words, “what they were doing was a sexual assault, and that if they were anyone but the government, the act would be illegal.”
The controversy about the invasive pat-down is different from the controversy about advanced imaging. Advanced imaging raises concerns about privacy, which TSA has tried to ameliorate by various technological means, most notably separating the personnel who escort travelers through the machine from those who read the scans. The invasive pat-down is objectionable for similar privacy reasons, but also because it is widely perceived as humiliating to the traveler. Photos that have been published showing invasive pat-downs suggest that TSA officers also find the task humiliating.
And there is no option to the invasive pat-down. Tyner’s video clearly shows the TSA supervisor explaining — in a professional manner, it should be noted — that the only way Tyner could avoid it was to not board his flight and leave the airport. According to Tyner, even this option was subsequently withdrawn and he was threatened with a $10,000 civil fine if he left the airport without submitting to the invasive pat-down.
The result of an Invasive pat-down is either a “positive” or a “negative.” A positive means a potential non-metallic threat, such as the presence of nitrate, was detected; a negative means one was not. At this stage, one cannot assume that all positives are bona fide threats, nor can one assume that all negatives are proof of the absence of a threat. For this reason, the event tree divides each positive outcome into “false” positives and “true” positives. A false positive is like a false fire alarm: the risk trigger was tripped, but subsequent inspection reveals that no fire was actually present. A true positive is exactly what it sounds like: a genuine threat to the safety of the airport or air travel.
The same goes for each “negative.” There are “true” negatives (the overwhelming majority of pat-downs that reveal no safety threat) and “false” negatives (the case in which a genuine safety threat is missed). So the event tree also divides negative results from the invasive pat-down test into true negatives and false negatives.
Here is where the results of the security regime are finally revealed. The system either intercepts a genuine security threat, which is marked by a green box labeled “Yes,” or it fails to intercept one, which is marked by a red “No” box. Note that each of the red “No” boxes is the result of a false negative.
TSA wants to eliminate false negatives — that is, make the red “No” boxes as rare as possible. Both the advanced imaging devices and the Invasive pat-downs are intended to accomplish this goal. Of course, every incremental effort made to reduce false negatives comes at a cost to travelers. This cost has two forms: (1) the cost of the screening regimen itself, including both intangible costs such as delay and intangible costs such as lost privacy and (especially) dignity; and (2) the cost of raising the rate of false positives. TSA cares about false positives because they slow down the screening process. Travelers care about the delays caused by false positives, but they also care because false positives force them to submit to additional, and more intensive screening, with all the attendant tangible and intangible costs mentioned above. No doubt, TSA cares about these costs, but it is inconceivable that it cares as much about them as travelers do.
How the TSA Security Regime Invites Terrorism
From this analysis, it is easy to prescribe the best path for a terrorist armed with a non-metallic weapon to follow. This path is illustrated in the chart below, with the specific pathway highlighted in red. It involves choosing a security lane with a metal detector and making absolutely sure not to wear any metal to ensure that the metal detector does not ping a positive. Doing so virtually ensures there will be no invasive pat-down.
The only way TSA can prevent this is to replace all metal detectors with advanced imaging devices. Until it can do this, it can institute invasive pat-downs as a stop-gap measure. Whether the invasive pat-down is effective is beside the point. If it is offensive enough, TSA can subtly persuade travelers to submit to advanced imaging, if for no other reason than to avoid the degradation of being groped.
The Fundamental Flaw in TSA’s Security Regime
TSA’s system is based from the ground up to detect and intercept weapons, not dangerous people. Thus, technological remedies such as advanced imaging represent the only available option. Even if they were 100% effective, invasive pat-downs are too time-consuming to implement except as responses to “positives” resulting from the operation of higher technologies.
Recall that TSA insists on screening for weapons, not dangerous people. Therefore, the only solutions TSA will consider are technological ones.
Of course, other security models are available. Other countries screen for dangerous people, though it is not clear this could be scaled to match the US airline volume:
Security is almost universally considered most effective at Ben-Gurion International Airport in Tel Aviv, Israel. No plane operating from there has been successfully attacked since 1972, when 24 people were killed in a hijacking by a terrorist group calling itself the Japanese Red Army.
The state airline, El Al, which coordinates security at Israel’s airports, is unapologetic about its use of passenger profiling — making judgments about a passenger’s likelihood of posing a threat based on his or her background, behavior and associations.
Passengers can be questioned on arrival at the airport entrance and again at the terminal entrance. And all passengers are questioned individually once they’re inside the terminal by security agents looking for abnormal behavior or any other reason to be suspicious.
“We don’t need to spend one dollar to buy body scanners,” said [former director of global security at El Al Israel Airlines Isaac] Yeffet, adding in an interview on msnbc TV that Muslim passengers would never accept the explicit imagery generated by the scanners.
Another option is to reincarnate the Registered Traveler program in a useful way. RT only enabled travelers to go to the front of the security queue, a benefit to be sure, but not one that justifies extensive background checks and biomarkers. Former American Airlines CEO Robert Crandall says these features should be the backbone of a “trusted traveler” program:
What we ought to be doing is dividing people into those who are clearly not a threat. We should introduce and use a trusted traveler program by which people can sign up, have a thorough background check, and thus provide adequate intelligence with regard to the probability of their being a threat.
Profiling is politically incorrect. But the reality is that virtually every security threat has been from a relatively small group of people — young, Middle-Eastern men. They are clearly a higher security threat and we should focus our resources on those people likely to be a security threat.
We should recognize that what we are looking for are probable terrorists. We’re not looking for things. We’re looking for people.