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Whole Body Imaging Technology and Body Scanners ("Backscatter" X-Ray and Millimeter Wave Screening)


EPIC has filed a lawsuit to suspend the deployment of body scanners at US airports, pending an independent review. Body scanners produce detailed, three-dimensional images of individuals. Security experts have described whole body scanners as the equivalent of "a physically invasive strip-search." The Transportation Security Administration operates the body scanner devices at airports throughout the United States. On July 2, 2010, EPIC filed a petition for review and motion for an emergency stay, urging the District of Columbia Court of Appeals to suspend the Transportation Security Administration's (TSA) full body scanner program. EPIC said that the program is "unlawful, invasive, and ineffective." EPIC argued that the federal agency has violated the Administrative Procedures Act, the Privacy Act, the Religious Freedom Restoration Act, and the Fourth Amendment. EPIC cited the invasive nature of the devices, the TSA's disregard of public opinion, and the impact on religious freedom.

Latest News/Events

  • EPIC to Request Kavanaugh White House Records on Warrantless Wiretapping, Mass Surveillance Programs + (Jul. 30, 2018)
    EPIC is planning to submit a Freedom of Information Act request to the Bush Library and the National Archives and Records Administration for records concerning programs of mass surveillance and Supreme Court nominee Brett M. Kavanaugh. Kavanaugh served as Assistant to the President and Staff Secretary for President George W. Bush between July 2003 and May 2006. During that time, the Bush administration undertook a wide range of mass surveillance programs, including the warrantless wiretapping of Americans, which was later deemed unlawful. On the federal appellate court, Judge Kavanaugh wrote that a suspicionless surveillance program "is entirely consistent with the Fourth Amendment." "Critical national security need outweighs the impact on privacy occasioned by the program," wrote Kavanaugh. Other programs backed by the White House when Judge Kavanaugh served as White House Staff Secretary include Total Information Awareness, airport body scanners, and Real ID.
  • Senators Urge DHS to Address Concerns Over Facial Recognition at Airports; Conduct Public Rule-Making + (May. 11, 2018)
    In a letter to DHS Secretary Kirstjen Nielson, Senators Edward Markey (D-MA) and Mike Lee (R-UT) urged the agency to promptly conduct a public rulemaking on the agency's biometric exit program prior to any expansion of the program. The program, currently implemented in nine U.S. airports, requires travelers on departing international flights to submit to facial recognition identification. The Senators requested that DHS determine the accuracy of the technique and the procedures for collecting passenger data. EPIC is currently pursuing documents about the biometric exit program, but documents EPIC obtained about a related program that tested iris and facial recognition scanning at the border revealed that the technology did not perform operational matching at a "satisfactory" level. An earlier EPIC lawsuit against the DHS led to the removal of backscatter x-ray devices — "body scanners" — at US airports.
  • EPIC Urges Congress to Suspend Facial Recognition At US Airports + (Feb. 26, 2018)
    EPIC has sent a statement to the House Homeland Security Committee in advance of a hearing on the Transportation Security Administration. EPIC urged the Committee to limit the collection of biometric data at US airports. EPIC described the growing use of facial recognition that capture the images of US travelers. EPIC also pointed to a recent study that found racial disparities with the technique. EPIC previously pursued a significant lawsuit against the TSA that led to the removal of x-ray body scanners from US airports. EPIC is currently seeking records from Customs and Border Protection concerning the accuracy of facial recognition.
  • More top news

  • Republican DACA Bill Would Expand Use of Drones, Biometrics + (Feb. 21, 2018)
    The Secure and Succeed Act (S. Amdt. 1959 to H.R. 2579), sponsored by several Republican Senators, would link DACA with hi-tech border surveillance. Customs and Border Protection would use facial recognition and other biometric technologies to inspect travelers, both US citizens and non-citizens, at airports. The bill also establishes "Operation Phalanx" that instructs the Department of Defense—a military agency—to use drones for domestic surveillance. EPIC has pursued many FOIA cases on border surveillance involving biometrics, drones, and airport body scanners, In a statement to Congress, EPIC warned that "many of the techniques that are proposed to enhance border surveillance have direct implications for the privacy of American citizens."
  • EPIC Urges Senate to Block Biometric Collection At US Airports + (Sep. 28, 2017)
    EPIC has sent a statement to the Senate Commerce Committee following a hearing on the Transportation Security Administration. EPIC urged the Committee to limit the collection of biometric data at US airports. EPIC described the growing and regulated use of biometrics in US airports, often targeting US citizens. EPIC previous pursued a significant lawsuit against the TSA to limit the use of body scanners. EPIC is currently seeking records from Customs and Border Protection concerning the agency's use of facial recognition for a biometric entry/exit program at airports. EPIC has also objected to a proposal to increase the collection of biometric data for the TSA Pre-Check program.
  • EPIC Obtains Final Report on "Face ePassport Air Entry Experiment" + (Sep. 8, 2017)
    As the result of a Freedom of Information Act request, EPIC has obtained a report on the use of face recognition on travelers entering the United States at Dulles Airport. The report was obtained after EPIC filed a lawsuit against Customs and Border Protection for documents about the agency's biometric entry/exit program, expedited by Executive Order 13769. As the report was heavily redacted, EPIC's FOIA lawsuit is ongoing. In a statement to the House Homeland Security Committee earlier this year, EPIC warned that biometric identification techniques, such as facial recognition, lack proper privacy safeguards. EPIC has extensively litigated airport screening techniques, including EPIC v. TSA, concerning airport body screening.
  • TSA Proposal to Inspect Books at US Airports Raises First Amendment Concerns + (Jun. 27, 2017)
    The TSA is considering a requirement to remove books from carry-on luggage for inspection during security screenings. The procedure raises concerns that individuals may be singled out for their religious and political beliefs, implicating core First Amendment values. In 2015 a college student won a $25,000 settlement after he was detained by the TSA for carrying Arabic flash cards. EPIC has pursued litigation against invasive airport screening techniques. In EPIC v. DHS, EPIC successfully sued to require the Department of Homeland Security to obtain public comment on the use of body scanners in U.S. airports. The litigation also led to the removal the backscatter x-ray devices from airports. EPIC recently filed a FOIA request to determine why US travelers returning to the United States are subject to biometric identification. In numerous cases, including a recent case before the US Supreme Court, EPIC has argued for the freedom to without government surveillance.
  • DC Circuit Rules in Second EPIC Airport Body Scanner Case + (May. 30, 2017)
    In a cursory per curium opinion, the D.C. Circuit denied EPIC's petition for review of the TSA's final rule mandating body scanners in U.S. airports. EPIC argued in EPIC v. DHS II that the TSA had failed to justify body scanners as compared with less invasive, more effective screening techniques, such as magnometers combined with explosive trace detection. Public comments overwhelmingly favored EPIC's recommendations to the federal agency. EPIC also argued that the TSA's decision to end the opt-out was contrary to the DC Circuit's earlier opinion EPIC v. DHS I which held that passengers could opt-out of the invasive screening technique. As Judge Ginsburg explained in the earlier case, "Despite the precautions taken by the TSA, it is clear that by producing an image of the unclothed passenger, an AIT scanner intrudes upon his or her personal privacy in a way a magnetometer does not." Judge Ginsburg further said, "any passenger may opt-out of AIT screening in favor of a patdown, which allows him to decide which of the two options for detecting a concealed, nonmetallic weapon or explosive is least invasive."
  • EPIC to Congress: Examine TSA Secrecy + (Apr. 26, 2017)
    EPIC has sent a statement to the House Committee on Homeland Security for an oversight hearing on the Transportation Security Administration. EPIC has objected to the TSA's refusal to release information the agency designated as "sensitive security information" that is pertinent to EPIC's ongoing case against TSA regarding airport body scanners. EPIC said that the TSA is "seeking to hide its decision making behind this cloak of secrecy." Congress also criticized the TSA's use of the SSI designation in an extensive report on "Pseudo Classification." In the statement for the Committee, EPIC also objected to the eye scanning of US travelers at US airports.
  • EPIC to Congress: Examine TSA Secrecy + (Mar. 2, 2017)
    EPIC has sent a letter to the House Committee on Oversight for a hearing on the Transportation Security Administration. EPIC has objected to the TSA's refusal to release information designated as "sensitive security information" that is pertinent to EPIC's ongoing case against TSA regarding airport body scanners. EPIC said that "seeking to hide its decision making behind this cloak of secrecy." The House Committee has also criticized the agency's use of the SSI designation. EPIC also raised concerns about the eye scanning of US travelers at US airports as well as the TSA's statement that they will no longer accept drivers licenses from states that oppose "REAL ID".
  • EPIC Files Suit to Block "Invasive and Ineffective" Airport Body Scanner Program + (Sep. 27, 2016)
    EPIC has filed the opening brief in EPIC v. TSA II with the federal appeals court in Washington, DC, challenging the Transportation Security Administration's continued use of body scanners in US airports. TSA issued a regulation mandating the use of body scanners across the country more than five years after the court in EPIC v. TSA ordered the agency to "promptly" solicit public comments on the controversial body scanners program and nearly a decade after the agency deployed the scanners without public comments. EPIC told the court that the TSA's regulation entrenches body scanners over more effective less intrusive screening techniques,  and undermines  the legal right of passengers to opt out. EPIC wrote that the TSA has failed to "justify the use of invasive screening techniques, or to provide the public with an opportunity to respond to the denial of the passenger opt-out right."
  • EPIC Sues TSA to Block Mandatory Body Scanners at US Airports + (May. 2, 2016)
    EPIC has filed a lawsuit challenging the Transportation Security Administration's regulation for airport body scanners. The TSA announcement came nearly five years after a federal appeals court ordered the agency to "promptly" solicit public comments on the controversial screening procedure. Public comments overwhelmingly favored less invasive security screenings. But the TSA decided it may now mandate body scanners at US airports. In 2011, EPIC challenged the intrusive and ineffective TSA screening procedure. EPIC's new lawsuit challenges the regulation because it "denies passengers the right to opt out" of body scanner screening. EPIC also challenged the effectiveness of airport body scanners and the TSA's failure to recommend less invasive security screening.
  • TSA Releases New Body Scanner Document to EPIC + (Apr. 25, 2016)
    In response to an EPIC FOIA request, the Transportation Security Administration has released a document describing the technical capabilities of the airport body scanners. EPIC previously obtained documents from TSA revealing that body scanners can record, store, and transmit digital strip search images of airline passengers. Last month, the TSA issued a regulation on airport body scanners, nearly five years after a federal appeals court ordered the agency to "promptly” undertake a rule making. In 2011, EPIC successfully challenged the TSA's unlawful deployment of airport body scanners. Despite public comments that overwhelmingly favor less invasive security screenings, the TSA plans to use invasive body scanners at US airports. The TSA also said it may mandate airport body scanners, even though the agency previously told the D.C. Circuit that the body scanner program was optional and the federal appeals court upheld the program, relying on the agency’s statements.


Post-September 11, airline travel security has invoked the increased use of technology and better training of security personnel as a means of improving travel security. Some of these proposals, such as improved training for airport screeners, checking all bags for bombs, strengthening cockpit doors, and placing air marshals on flights, do not implicate privacy interests and are sound security measures. Others, however, present privacy and security risks to air travelers because they might create data files directly linked to the identity of air travelers. These files if retained could provide the basis for a database of air traveler profiles. The Transportation Security Administration utilizes two technologies to capture naked images of air travelers - backscatter x-ray technology and millimeter wave technology.

In 1895 x-rays1 were discovered by Wilhelm Röntgen.2 This discovery of how to look through an object to observe details beneath has advanced to include new techniques. One such technique called "backscatter" X-Ray is based on "the emergence of radiation from that surface of a material through which it entered. Also used to denote the actual backscattered radiation.3"

backscatter imageThe application of this new x-ray technology to airport screening uses high energy x-rays that are more likely to scatter than penetrate materials as compared to lower-energy x-rays used in medical applications. Although this type of x-ray is said to be harmless it can move through other materials, such as clothing.

A passenger is scanned by rastering or moving a single high energy x-ray beam rapidly over their form. The signal strength of detected backscattered x-rays from a known position then allows a highly realistic image to be reconstructed. Since only Compton scattered x-rays4 are used, the registered image is mainly that of the surface of the object/person being imaged. In the case of airline passenger screening it is her nude form. The image resolution of the technology is high, so details of the human form of airline passengers present privacy challenges.

Airport security has undergone significant changes since the terrorist attacks of Sept. 11, 2001. Recently, the Transportation Security Administration (TSA) announced a proposal to purchase and deploy "Whole Body Imaging" X-ray machines to search air travelers at all airports. TSA said it believes that use of the machines is less invasive than pat-down searches. However, these machines, which show detailed images of a person's naked body, are equivalent to a "digital strip search" for all air travelers. This proposal, along with the agency's controversial plan to profile air travelers, shows extraordinary disregard for the privacy rights of air travelers. The Department of Homeland Security is requesting $72 million to invest in detection systems, which includes funding for the backscatter machines, which cost between $100,000 and $200,000 each.

The backscatter machines use high-energy X-rays that are more likely to scatter than penetrate materials as compared to lower-energy X-rays used in medical applications. Although this type of X-ray is said to be harmless, it can move through other materials, such as clothing. When being screened, a passenger is scanned by high-energy X-ray beam moving rapidly over her body. The signal strength of detected backscattered X-rays from a known position then allows a highly realistic image to be reconstructed. In the case of airline-passenger screening, the image is of the traveler's nude form. The image resolution of the technology is high, so the picture of the body presented to screeners is detailed enough to show genitalia. These images are not necessarily temporary - screeners can save the body images to the system's hard disk or floppy disk for subsequent viewing on either "the system monitor or on any IBM compatible personal computer with color graphics."

Backscatter X-Rays and Transportation Screening

The Transportation Security Administration claims that is not storing detailed images of passengers screened by the system. The agency also states that it is providing a screening option for passengers who object to screening by the technology. However, the technology is designed to accomplish what has been described on this page, and until the process of assuring that the claims of the agency are enforced--questions will remain about the use of the technology. EPIC will make available on this page aviation security and privacy -related documents it obtains from the government under the Freedom of Information Act law about the adoption of "backscatter" x-ray technology intended for use in screening air travelers.

womanThe stated goal of these new proposals is to rely on technology to reduce the "hassle factor" in airports and to reduce security threats. The core idea is to focus security resources on suspicious travelers, while ensuring that most people are not inconvenienced by heightened security. Terrorists, however, have been known to go to great lengths to look like most people. Will a technology that will capture detailed images of potentially all airline travel passengers lead to greater safety? Current technology can successfully detect dangerous substances, firearms and other weapons without backscatter x-ray imaging of passengers. Can the goal of safe air travel be reached without reproducing a digital image of a passenger's body? It has long been recognized by security experts that it is impossible to eliminate all threats to airline travel. Is the application of "backscatter" x-ray technology a deterrent and not a solution to perfect airline travel safety? If this is true, then is the trade off in passenger privacy worth the effort to deter terrorists? The application of security technology and increased passenger screening has also resulted in an increased detection of non-violent criminal offenses. Is the application of "backscatter" x-ray technology to screen airline passengers more than just a means of detecting terrorists?

In 2009, the TSA announced that Whole Body Imaging would replace metal detectors at airport security check points. This is a marked departure from the earlier promises by the agency that the technology would only be used for secondary screening of air travel passengers.

Airports Currently Using Whole Body Imagaing Technology

  • Albuquerque International Sunport Airport
  • Hartsfield-Jackson Atlanta International Airport
  • Baltimore/Washington International Thurgood Marshall Airport
  • Ronald Reagan Washington National Airport
  • Denver International Airport
  • Dallas/Fort Worth International Airport
  • Detroit Metro Airport
  • Indianapolis International Airport
  • Jacksonville International Airport
  • McCarran International Airport
  • Los Angeles International Airport
  • Miami International Airport
  • Phoenix Sky Harbor International Airport
  • Raleigh-Durham International Airport
  • Richmond International Airport
  • San Francisco International Airport
  • Salt Lake City International Airport
  • Tampa International Airport
  • Tulsa International Airport

Jan. 2010 NPC Event Materials

Latest News


Identification Schemes


Other Documents


  • Paper on the limitations of profiling, Roger Clark, Australia National University.
  • ACLU testimony before White House Commission on "Civil Liberties Implications of Airport Security Measures" (September 5, 1996).
  • Letter to Privacy Journal editor Robert Ellis Smith from the FAA denying Smith's request for a copy of the FAA Security Directive on identification of airline passengers.
  • HotWired article "Fear of Flying" on proposals. (September 11, 1996).

Other Airline Passenger Screening Resources

  • FAA Proposes Profiling Regulations. The Federal Aviation Administration published proposed regulations on April 19, 1999, governing "Security of Checked Baggage on Flights Within the United States." The draft rules detail the use of computer profiling techniques to identify suspicious passengers.
  • Airline Passenger Profiling Goes Into Effect. The Computer Assisted Passenger Screening System was scheduled to be phased in nationwide beginning on January 1. Under the system, passengers who "fit the profile" will be selected for heightened security measures, which can include a thorough search of their luggage, intrusive personal questioning, tagging of luggage with orange tape, and a physical escort from the check-in counter to the airport gate by security personnel. The ACLU is providing an online complaint form for passengers targeted by the profiling system.
  • Microsoft Chief Architect Charles Simonyi tells what happens when you "fit the profile" (from Slate).
  • Proposed FAA rule for collecting personal information including name, address, Social Security Number, Date of birth and next of kin for every domestic passenger.
  • General Account Office report, Aviation Safety and Security: Challenges to Implementing the Recommendations of the White House Commission on Aviation Safety and Security (Testimony, 03/05/97, GAO/T-RCED-97-90).
  • The Gore Commission has released its final report recommending passenger profiling. A coalition of 17 groups has sent a letter to Gore opposing ID checks, profiling, new x-ray technologies and excessive secrecy by the FAA in making decisions.

Legislative History

HR 1271. FAA Research, Engineering, and Development Authorization Act of 1997. Funds FAA projects for new surveillance technologies such as advanced x-ray systems for individuals. Introduced on 4/10/97 by Morella (R-Md). Referred to the House Committee on Science. Approved by Committee 4/16/97. Reported to the House H. Rept. 105-61 (CR H1714) on 4/21/97. Measure adopted on 4/29/97, RC #95 (414-7), (CR H1995). Referred to Senate Committee on Commerce, Science and Transportation (CR S3843) on 4/30/97.

Bill Passed the Senate: 11/13/1997
Mr. Sensenbrenner moved that the House suspend the rules and agree to the Senate amendments: 2/3/1998
Bill Passed the House by a voice vote: 2/3/1998 3:07pm:
Bill Signed into Law by President Clinton: 2/11/1998
Became Public Law No: 105-155.



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