The ACLU believes that three principles should be applied to proposals to increase air travel safety.
In applying these three principles, the ACLU supports the use of effective security measures to enhance airport safety, which 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 a number of 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, and luggage matching of all passengers.
There have been proposals, including those made by Senator John Edwards, D-NC, 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. To be effective, the government would have to have the iris scan or digital fingerprint of every person living in the United States. 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 a variety of 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 caught 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 will create a false sense of security. Terrorists will not be lining 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 machines such as - Body Search - are in use in some airports by the Customs Service to search for drugs and other contraband. The ACLU is concerned that these searches have been conducted without good cause and based on profiles that are racially discriminatory. In addition, these machines are capable of projecting an image of a passenger's naked body. We oppose using this 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 pre-requisite to boarding a plane. However, such technology may be used in place of an intrusive search, such as a body cavity search, when there is probable cause sufficient to support such a search.
The ACLU opposes the use of profiles based on race, religion or ethnicity. Profiles are used in lieu of probable cause to subject some passengers to heightened security. We oppose 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 criminal. It is unconstitutional to single out any person because of their race or ethnicity. It is, however, permissible to use race, in conjunction with other information, if race is one of a number of characteristics used to describe a particular suspect.