American Civil Liberties Union

Testimony Regarding the U.S. Transportation Security Administration’s Physical Screening of Airline Passengers and Related Cargo and Airport Screening

Principles for Evaluating Physical Screening Techniques and Technologies Consistent with Constitutional Norms

Before the U.S. Senate Committee on Commerce, Science, and Transportation

Submitted by Timothy D. Sparapani,
Legislative Counsel

Dirksen Senate Office Building, Room 562

The Honorable Chairman Stevens and Ranking Member Inouye:  the American Civil Liberties Union (“ACLU”), a nationwide non-partisan organization with hundreds of thousands of activists, members and affiliates in virtually every state, respectfully submits this testimony.  We appreciate the opportunity to submit this written statement for the record of this hearing on physical screening of cargo and passengers.  In the statement, the ACLU first lays out six principles of airline security, and then applies those to particular security measures, rejecting some and endorsing others.

The ACLU urges Committee members to embrace the concept that Americans can and must be both safe and free, and that physical screening technologies should be proven to be both effective and minimally intrusive to protect civil liberties, particularly privacy interests.  Further, the ACLU urges Congress eliminate support for proposed airline passenger pre-screening programs such as Secure Flight and Registered Traveler in favor of more effective security measures.  Certain minimally intrusive technologies focused on addressing a genuine security threat – such as explosives that are not discoverable through use of conventional metal detectors – are preferable to the fatally flawed approaches taken in such pre-screening programs. 

The ACLU believes that Congress should apply the following principles in deciding which proposals it would support to increase air travel safety: 

Principles of Airline Security

• New physical security technologies must be genuinely effective, rather than creating a false sense of security. 
  
• The level of intrusion – the degree to which a proposed measure invades privacy – should reflect the level of risk, and, if both are effective, the least intrusive physical screening technology or technique should always trump the more invasive technology.
• Given limited Homeland Security funding, Congress must insist that those technologies that reduce the gravest threats be implemented first.
• The physical security technologies employed must be focus on accomplishing the critical objective that authorizes their application – increasing passenger aviation security.  Neither TSA’s screening employees nor the machines they operate should be diverted to search for illegal contraband that does not pose a threat to aviation security. 
• Minimally intrusive physical screening technologies should be implemented in lieu of ineffective passenger pre-screening proposals, such as Secure Flight and Registered Traveler. 
  
• Security measures should be implemented in a non-discriminatory manner. Travelers should not be subjected to intrusive searches or questioning based on race, ethnic origin, country of origin, or religion.  Rather, heightened security measures should be employed where neutral criteria show that a person poses a physical threat to aviation.

Each of these principles is discussed in detail below.

II.  Congress Must Insist that Each Technology TSA Adopts Satisfies the Principles of Airline Security

A.      Principle 1:  Physical Screening Techniques and Technologies Must Be Effective, or they Should Not be Utilized or Funded

            Congress should not allow TSA to fund or implement physical screening techniques and technologies that do not substantially advance passenger aviation security.   The wisdom supporting this principle is obvious: funds to increase aviation security are limited, and any technique or technology must work and be substantially better than other alternatives to deserve some of the limited funds available.  It therefore follows that before Congress invests in the purchase of technologies from private vendors, it must demand evidence and testing from neutral parties that the technologies have a great likelihood of success – i.e., that they prevent terrorists from bringing explosives and weapons onto planes.  Technologies with such low probabilities for success unnecessarily infringe travelers’ personal privacy and could harm civil liberties, while doing little to increase passenger aviation security.  The ACLU believes that the American people deserve real security if they are to accept administrative searches in the form of physical screening, not just the purchase of machines that provide a false sense of security.

B.      Principle 2:  The Least Intrusive Techniques and Technologies are More Likely to Withstand Constitutional Scrutiny

Because the application of administrative searches for aviation security burdens the constitutionally protected right to privacy, Congress must insist that all new physical screening techniques and technologies authorized be the least intrusive necessary to accomplish the screening of aviation passengers, their bags, and cargo.  The administrative search exceptions to the Fourth Amendment demand that where Congress has a choice between two equally effective technologies, it must only authorize the technology that will least burden the traveling public. 

C.       Principle 3:  Prioritize the Techniques and Technologies Targeted at the Gravest Threats

Focus on the greatest threats first.  As TSA Director Kip Hawley has stated, since the commercial airplanes hardened their cockpit doors and terrorists have lost the element of surprise, it is more likely that any terrorists would attempt to blow up a plane with explosives than it is that they will try to hijack a plane to use as a missile.  Thus, the greatest threat to aviation security is likely to be from explosives, which cannot be addressed through passenger pre-screening programs.  As a result, searches for conventional weapons, while important, are less vital to aviation security than insisting that 100 percent of cargo, luggage, and carry-on bags are screened for explosives.  Through the power of the purse, Congress should help TSA to prioritize its efforts to deal with this threat and direct its energies to implement effective technologies that accomplish this goal first. 

D.       Principle 4:  Techniques and Technologies that Impact Personal Privacy Must be Narrowly Tailored to Accomplish the Sole Objective of Improving Passenger Aviation Security

Because physical search techniques and technologies used in domestic air travel affect privacy interests protected by the Fourth Amendment, TSA may only deploy and Congress should only authorize those techniques and technologies that are minimally intrusive to achieve the goal of increasing passenger aviation security.  Repeated tests by various federal agencies after 9/11 demonstrate that screeners regularly fail to identify weapons and explosives, reminding us that screeners and screening technologies need to remain focused on their core mission:  stopping explosives, weapons and their components from being brought or shipped on planes.  The ACLU believes that the flying public expects and deserves such a focus, particularly since other federal, state and local government agencies have other means of searching for and identifying contraband.   

E.     Principle 5:  Effective and Minimally Intrusive Physical Screening Technologies Should be Implemented while Proposed Passenger Prescreening Programs, Such as Secure Flight and Registered Traveler, Should be Eliminated

            Passenger prescreening programs are not effective, in that they treat everyone as a suspect, nor are they minimally intrusive because they require review of substantial amounts of personally identifiable information to assign passengers a risk assessment.  TSA’s focus on proposed passenger prescreening programs has diverted scarce resources since 9/11 from those techniques and technologies that could lessen the gravest threat to passenger aviation security by detecting explosives brought on or shipped in planes.  This diversion has been costly because proposed prescreening programs – such as Secure Flight and Registered Traveler, with their myriad constitutional, technological, security and efficiency infirmities – are only slightly closer to implementation than when they were first proposed shortly after September 11, 2001.  Yet, as has been made clear by the U.S. Government Accountability Office and Congressional hearings, these programs do not substantially improve passenger aviation security.  Further, they are prohibitively expensive and privacy invasive.  More importantly, TSA’s insistence on moving forward with passenger prescreening likely has led to TSA’s failure to implement robust, narrowly tailored explosives and weapons screening of all carry-on bags, luggage, and cargo.  Thus, this divergence of attention and resources has been, and continues to be, a potentially dangerous one. 

The ACLU once again urges Congress to redirect TSA’s efforts towards implementing effective and minimally intrusive physical screening technologies while eliminating authorization for passenger prescreening programs and shifting funding to purchase those narrowly-tailored physical screening technologies.  The result will surely be speedier and more certain improvements in passenger aviation security.

F.      Principle 6:  Physical Screening Techniques and Technologies May Not Be Applied in a Discriminatory Matter

Longstanding constitutional principles require that no administrative searches, either by technique or technology, be applied in a discriminatory matter.  The ACLU opposes the use of profiles based on race, religion, ethnicity, or country of origin.  Profiles can be used in lieu of evidence to subject some passengers to heightened scrutiny.  The ACLU opposes the use of profiles based on these factors because they are not only unfair, but are an ineffective means of determining who may be a terrorist.  It is unconstitutional to single out any person because of their race, religion, country of origin or ethnicity.  It is, however, permissible to, for example, use race in conjunction with other information, if race is one of several characteristics used to describe a particular suspect.  The Israeli government discovered that shortly after it devised a profile of the likely terrorist based on race, gender and age, that the terrorist organizations it was trying to stop changed the profile of the suicide bomber.  Thus discriminatory profiling techniques to select individuals for secondary screening actually may create a security weakness by focusing too few security screening resources on travelers who do not fit the profile.  The ACLU points out that America’s sophisticated, patient enemies may well seek to exploit such a discriminatory scheme. 

            Some physical screening techniques and technologies under consideration deserve further scrutiny, in part because they fail to satisfy one or more of the principles of good airline security.  Some, discussed below, are ineffective or inefficient.  Congress should block authorization or funding of these programs unless and until they can be modified to meet the principles and thereby lessen the threat they pose to personal privacy and civil liberties.

            The ACLU has long been concerned about the increased use of pat-down searches post-9/11, but we recognize that secondary screening – perhaps including the use of pat-downs – may be acceptable when a metal or explosives detection device suggests the presence of a weapon or explosives.  Thus, the level of intrusion would be keyed to a risk. Pat-down searches in the absence of other evidence are unnecessarily invasive.  Further, TSA’s use of pat-downs have led to substantial numbers of complaints about groping of passengers breasts, buttocks, and genitalia.  Congress must continue to monitor this situation to ensure that pat-downs only occur when necessary. 

B.    Biometric Identifiers Should be Used Only for Airport Personnel and Not for the General Traveling Public

There have been proposals to use biometric techniques to accurately identify airport personnel who have access to sensitive areas.  The ACLU does not oppose using biometric identification techniques with a proven record of accuracy – such as iris scans or digital fingerprints – to identify and authenticate persons working in secured areas of airports.  The error rate for those technologies is very low, and using the technology could increase security without compromising civil liberties.  This represents a good application of modern technology.  Biometric identifiers collected from airport and airline workers should not, however, be used for unrelated purposes. 

The ACLU does, however, oppose using this technology for all airline passengers because it is so intrusive. To be effective, the government would have to have the iris scan or digital fingerprint of every person living in the United States and probably that of anyone traveling through America’s airways.  This would be the high-tech equivalent of creating a National ID system. Doing so would raise grave privacy concerns and, furthermore, it would be unrealistic to expect that high quality images could be easily obtained and maintained on the tens of million of Americans who travel by air. 

Not every technological solution makes sense and will enhance safety. For example, many have proposed using facial recognition technology for several uses in airports.  But this modern technology is notoriously inaccurate.  One government study, for example, showed a 43 percent error rate of false negatives – a failure to properly identify posed photographs of the same person taken 18 months apart.  In other words, persons who should have been matched to their own photo were not.  Put another way, if Osama Bin Laden were to stare in the camera at one of our airports, the technology would have no more chance than a coin toss of properly identifying him. 

Some have also proposed using video surveillance to scan crowds at airports and compare those images with photographic databases.  Facial recognition technology is even less accurate in those circumstances, and its use will not only create privacy problems for law-abiding passengers, but also will create a false sense of security.  Terrorists will not line up to be photographed for security databases and will quickly learn the techniques for obscuring their identity.  There is no reason to jeopardize our privacy for measures that will create a false sense of security. 

There are some security measures that are extremely intrusive and should only be used when there is good cause to suspect that an individual is a security risk.  Low-dose X-ray backscatter machines – such as those offered by Rapiscan, Inc. and AS & E – are used by the Customs Service in some airports to search for drugs and other contraband. The ACLU is concerned that these searches – akin to Superman’s X-ray vision– have been conducted without good cause and are based on profiles that are racially discriminatory.  In addition, these machines are capable of projecting a high-resolution image of a passenger's naked body.

Congress should prohibit X-ray backscatter’s use as part of a routine screening procedure.  Passengers expect privacy underneath their clothing and should not be required to display highly personal details of their bodies – such as evidence of mastectomies, colostomy appliances, penile implants, catheter tubes, and the size of their breasts or genitals – as a prerequisite to boarding a plane.  However, X-ray backscatter technology has tremendous potential to screen carry-on bags, luggage, and cargo.

            As discussed above, however, X-ray backscatter technology’s routine use likely will lead to increased passenger screening delays and will certainly require subsequent searches for numerous passengers.  For example, an image projected by X-ray backscatter that may look like a concealed gun or explosive device carried on a person will require TSA screeners to put the person through: (a) a conventional metal detector; (b) an explosives detection “puffer” machine; or (c) both.  Further, even if an object is identified, TSA screeners will then need to pat the individual in question down and likely ask them to remove their clothing to verify what the object in question may be.  Even the presence of a seemingly innocuously shaped item, such as a prosthetic device or implant, will require subsequent (and potentially humiliating) verification.  Thus, X-ray backscatter requires a tremendous invasion of privacy with little speed or efficiency gains.  The ACLU, therefore, recommends that Congress not authorize and fund TSA’s purchase of X-ray backscatter machines.

Behavioral patterning to select passengers for heightened security is troublesome because it gives so much discretion to screeners that often result in racial profiling.  Congress should not authorize TSA screeners to employ secondary screening simply because someone is sweating or wearing a jacket.  Oftentimes, people must run to make a flight, and others are chilled easily by air conditioning.  Similarly, it will be difficult to train TSA screeners to effectively distinguish between those who – because of their cultural experiences – are less likely to give straightforward answers to authority figures such as TSA screeners wearing uniforms, and those who may be intending to carry out an attack.  Such behavioral profiling may be only marginally helpful in identifying someone who poses a threat, but is a practice that is certainly likely to lead to abuse.

            The ACLU is not suggesting that TSA screeners ignore their own eyes and instincts when someone is behaving suspiciously.  However, the application of behavioral profiling in an environment – commercial air travel – that is highly stressful for many even frequent, experienced, business travelers, must be tempered with concerns for constitutional norms to prevent unnecessary erosions of civil liberties and personal privacy.   Rather, any searches or questioning should be based on neutral criteria. 

The use of particle sniffers that are tuned to detect molecular traces of explosives (“puffer machines”) hold out the potential for searches that preserve the privacy and dignity of passengers far more than pat-downs, physical searches, and backscatter X-ray scans.  If utilize, the ACLU believes they should remain focused on the legitimate administrative purpose of protecting airline safety (as opposed to looking for contraband, such as drugs), and that system should be implemented to minimize false positives and handle them in a way that preserves passengers’ dignity.  It has been reported that molecular “cousins” of certain explosives that could trigger many false alarms may include such substances as heart medicine and lawn fertilizers.  This poses the question:  how will those individuals who signal a false alarm be treated, both at that moment and in the future?  The ACLU recommends that Congress exercise oversight over the implementation of such “puffer” machines to ensure that the rate of false positives is not unacceptably high so that passengers are given an efficient, non-intrusive means of resolving concerns about a false signal.  This is particularly important where a search by TSA screeners shows that neither the passenger nor their carry-on bags and luggage are concealing a bomb or bomb-making components.  Congress must insist that if TSA employs puffer machines, it also must set up fair procedures to rapidly ensure that innocent passengers who raise false positives can reach their destination.

IV.            Conclusion

            The ACLU recommends that Congress apply the six principles articulated above when considering whether to authorize and fund physical screening techniques and technologies.  Those techniques and technologies that do not demonstrably improve aviation security should be rejected.  Among the others, the least intrusive means available for accomplishing the goal of reducing the gravest threats to aviation security should be implemented. In recommending Congress’ application of these principles, the ACLU supports the use of effective, narrowly tailored security measures to enhance airport safety that have minimal risk to privacy, maximum-security benefit, and reflect the level of risk. The ACLU believes that increased safety need not come at the expense of civil liberties. The ACLU has suggested several measures, such as: increased training for security personnel; heightened screening of airline and airport security personnel; strict control of secured areas of airports; measures to improve security at foreign airports; a neutral entity to which passengers can report lax security procedures; luggage matching of all passengers; and the screening of all luggage, carry-on bags and cargo for explosives and weapons, which would satisfy the principles articulated.