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.

Top News

  • Security Experts: EPIC Correct About Body Scanners-Invasive and Ineffective: The first independent analysis of backscatter x-ray body scanners corroborate the claims EPIC and others have made for several years: The scanners are invasive and ineffective. In a detailed report published in 2005, EPIC warned that the x-ray body scanners amounted to a virtual strip search and were an ineffective means of airport security. Freedom of Information Act documents later obtained by EPIC revealed that TSA could disable the body scanner's privacy settings, the nude images could be stored on the machines, and the scanners ran on a standard operating system making them vulnerable to outside security threats. EPIC and a coalition of civil liberties organizations then petitioned DHS Secretary Napolitano to suspend the program. When the DHS failed to do so, EPIC sued the agency. The D.C. Circuit Court of Appeals ruled in EPIC v. DHS that the agency must begin a public rule making. The backscatter X-ray scanners were subsequently removed from US airports. For more information, see EPIC: EPIC v. DHS (Suspension of Body Scanner Program) and EPIC: Whole Body Imaging Technology. (Aug. 22, 2014)
  • Congress Investigates Airline Privacy Practices: Senator John Rockefeller (D-WV) is currently seeking information from ten U.S. airlines concerning how airlines safeguard consumer traveler data. Senator Rockefeller has requested information regarding: (1) the type of information airlines collect; (2) airlines' data retention periods; (3) airline privacy and security safeguards governing consumer information; (4) whether consumers may access and amend their information; (5) whether airlines sell or disclose consumer information and if so, to whom do they disclose the consumer data; and (6) how airlines inform consumers about airline privacy policies governing consumer information. EPIC routinely urges the Department of Homeland Security to provide privacy protections for air travelers and end the agency's secret "risk-based" passenger profiling. For more information, see EPIC: Air Travel Privacy, EPIC: Passenger Profiling, EPIC: Secure Flight, and EPIC: EPIC v. DHS (Suspension of Body Scanner Program). (Aug. 20, 2014)
  • Senate to Hold Homeland Security Oversight Hearing: The Senate Judiciary Committee will hold an oversight hearing for the Department of Homeland Security. Secretary Jeh Johnson will testify. EPIC has objected to many of the agency's mass surveillance practices, including the secret profiling of American air travelers, the use of drones for aerial surveillance, the amassing of information on Americans into "fusion centers", and the collection of biometric identifiers. EPIC has also warned that the DHS Chief Privacy Officer has failed to safeguard privacy, a legal obligation for that office. According to the DHS, the number of privacy complaints increased in 2013. EPIC has several Freedom of Information Act case pending against the DHS. In an earlier case, EPIC determined the DHS was monitoring social media and news organizations for criticisms of the agency. Another EPIC case led to the removal of the x-ray backscatter devices from US airports. For more information, see EPIC v. DHS - Social Media Monitoring and EPIC v. DHS (Suspension of Body Scanner Program). (Jun. 10, 2014)
  • EPIC Settles FOIA Case, Obtains Body Scanner Radiation Fact Sheets: EPIC has received the documents that were the subject of EPIC's Freedom of Information Act appeal to the D.C. Circuit in EPIC v. DHS (Body Scanner FOIA Appeal). The agency had previously withheld test results, fact sheets, and estimates regarding the radiation risks of body scanners used to screen passengers at airports. EPIC challenged the lower court's determination that the factual material was "deliberative" and therefore exempt from the FOIA. After filing an opening brief to the D.C. Circuit, EPIC participated in a new appellate mediation program. As a result of the mediation, EPIC obtained not only the records sought, but also attorneys' fees. The fact sheets show that the agency did not perform a "quantitative analysis" of risks and benefits before implementing the body scanner program. EPIC addressed that concern in the 2011 lawsuit EPIC v. DHS (Suspension of Body Scanner Program). That EPIC case also had a favorable outcome, and ultimately resulted in the removal of backscatter x-ray scanners from US airports. For more information, see EPIC v. DHS - Body Scanner FOIA Appeal and EPIC v. DHS - Suspension of Body Scanner Program. (Jan. 10, 2014)
  • EPIC Appeals Secrecy of Body Scanner Radiation Documents: EPIC has challenged a District Court decision which allowed two federal agencies to withhold documents about airport body scanners, including test results, fact sheets, and estimates regarding radiation risks. In the opening brief to the DC Circuit Court of Appeals, EPIC argues that federal agencies may not withhold factual information under the "deliberative process privilege" in the Freedom of Information Act. EPIC said that under "under the standard adopted by the lower court, not only would the judgement of agency officials be exempt, but so too would reports or studies of any significance." For more information, see EPIC: DHS Body Scanner FOIA Appeal, EPIC v. DHS and EPIC v. TSA. (Oct. 3, 2013)
  • TSA Conducts Warrantless Searches Outside of Airports: The Transportation Security Administration has expanded its Visible Intermodal Prevention and Response (VIPR) program to perform warrantless searches at various locations, including festivals, sporting events, and bus stations. The VIPR program uses "risk-based" profiling and "behavior detection" to search and detain individuals. Members of Congress have opposed these searches, and the GAO has questioned the validity of TSA's behavior detection and dispelled behavior detection effectiveness. Last year, EPIC prevailed in a lawsuit against the TSA that revealed the agency's plan to deploy body scanners outside of the airport at bus stations, train stations, and elsewhere. For more information, see EPIC: EPIC v. DHS (Mobile Body Scanners FOIA Lawsuit). (Aug. 8, 2013)
  • EPIC Urges Federal Government to Stop Virtual Strip Searches in US Airports: EPIC has submitted extensive comments opposing the TSA's decision to deploy body scanners in US airports. The D.C. Circuit Court of Appeals forced TSA to accept public comment on the controversial screening program following EPIC's lawsuit in EPIC v. DHS. In that case, EPIC successfully challenged the TSA's unlawful deployment of the body scanners which rendered images of air travelers stripped naked. More than 5,000 comments were submitted by the public, many on behalf of organizations and associations, and almost all opposed the agency's decision. EPIC's comments described the lack of adequate privacy safeguards for the backscatter x-ray scanners, the ineffectiveness of the devices, and the potential health risks to travelers. EPIC urged the agency to end the body scanner program and instead use noninvasive walk through metal detector and explosive trace detection devices. The agency has already removed hundreds of backscatter devices from US airports. EPIC brought the lawsuit after earlier EPIC FOIA lawsuits uncovered documents that revealed the devices were capable of storing and recording images of naked air travelers. For more information, see EPIC: Comment on the TSA Nude Body Scanner Proposal. (Jun. 25, 2013)
  • TSA "Unplugs, Boxes Up, and Ships Back" X-Ray Body Scanners: The TSA has completed removal of the x-ray body scanners from US airports. The devices revealed detailed images of a person's naked body and have been described as "digital strip searches." The TSA action follows an Act of Congress and several lawsuits by EPIC. The TSA was forced to remove the machines after Congress required that the devices produce only generic image. And as result of EPIC v. TSA the TSA is currently required to accept public comments on its airport screening procedures. The public has until June 24, 2013 to voice its opinions. The millimeter wave devices remain in US airports. For more information, see: EPIC: Comment on the TSA Nude Body Scanner Proposal and EPIC: ATR lawsuit.

    Backscatter x-ray machines show detailed images of a person's naked body and have been described as "digital strip searches."

    (May. 30, 2013)
  • Public Opposes TSA Nude Body Scanners: Following a court mandate that the Transportation Security Administration receive public comment on airport body scanners, the public overwhelmingly opposes invasive nude body scanners. The court mandate was in response to EPIC's lawsuit in EPIC v. DHS, where EPIC successfully challenged the TSA's unlawful deployment of airport body scanners. The TSA will accept comments until June 24, 2013. The public has submitted almost 2,000 comments noting various problems with the scanners, including privacy violations, potential health risks, and the machine's inability to accurately detect threats. EPIC has recently filed appeals in two Freedom of Information Act cases seeking documents related to airport body scanner radiation risks and threat detection software. For more information, see EPIC: Comment on the TSA Nude Body Scanner Proposal, EPIC: Radiation Risks lawsuit, and EPIC: ATR lawsuit. (Apr. 23, 2013)
  • EPIC Appeals FOIA Decisions Concerning Body Scanner Information: EPIC has filed appeals in two Freedom of Information Act cases seeking documents related to airport body scanners from the Department of Homeland Security and the Transportation Security Administration. EPIC filed FOIA requests with the agencies seeking records related to radiation risks from body scanners and the threat detection software the machines use. The TSA is currently developing formal rules for the use of body scanners in response to a court order in one of EPIC's previous cases. Body scanners allow routine digital strip searches of individuals who are not suspected of any crime. For more information, see EPIC: Radiation Risks lawsuit and EPIC: ATR lawsuit, and EPIC: Suspension of Body Scanner Program. (Apr. 16, 2013)
  • TSA Broadens Use of 'Backscatter X-Ray' Machines That Conduct 'Virtual Strip Searches': The Transportation Security Administration is expanding the use of "backscatter X-ray" systems for passenger screening. The $100,000 refrigerator-size machines use "backscatter" technology, which bounces low-radiation X-rays off of a passenger to produce photo-quality images of travelers as if they were undressed. Computer processing partially obscures the image that is available to operators. TSA states that the agency will delete the raw images, but there is no law or regulation that prevents the agency from saving the original, detailed images. Until there is such a prohibition, EPIC believes funding for the program should be suspended. See EPIC's Spotlight on Surveillance and page on Backscatter X-ray. (October 11, 2007)
  • Field Tests Begin in Arizona on Backscatter X-Ray Machines: An X-ray machine aimed at detecting weapons and explosives hidden on passengers is scheduled to make its debut Friday at Phoenix's Sky Harbor International Airport. The "backscatter" will be in operation at Security Checkpoint B in Terminal 4. While any Terminal 4 ticketed passenger can pass through any checkpoint, the B concourse is primarily used by travelers on Tempe-based US Airways. (February 21, 2007)
  • Phoenix Airport to Use 'Backscatter' X-Ray on Travelers: Sky Harbor International Airport here will test a new federal screening system that takes X-rays of passenger's bodies to detect concealed explosives and other weapons. The technology, called backscatter, has been around for several years but has not been widely used in the U.S. as an anti-terrorism tool because of privacy concerns. (December 1, 2006)


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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