by Miriam Baker

Created on: December 10, 2010   Last Updated: December 14, 2010

Full-body scanners use a technology called millimeter wave imaging to create a three-dimensional image of the whole body, built up by the energy that the body reflects back to the scanner. This image scans the full surface of the body, but cannot see objects beneath the skin, such as implants. The process allows a Transportation Security Officer to quickly see any threatening objects that the person might be carrying.

The scanning equipment is able to store images, but the Transportation Security Agency (TSA) claim that scanners are always delivered to airports with this function disabled. The officers who operate the scanners at the airport cannot save any images, and are banned from entering the monitoring area with any device which could be used to take pictures, such as a camera phone. Each image is deleted in order to allow the next image to be taken.
    
The only person who sees a full-body scan image is a single security officer, whose job it is to check the images for suspicious objects. This officer works in a separate location to the scanning area, so that he or she never sees the person who is being scanned. No personal details, such as a passport number or name, appear on the scan, and faces are blurred, so the officer cannot identify or connect the image to an individual. The image doesn’t even appear on the officer’s screen unless the passenger fails to clear the screening.

If a suspicious object is found on the body, the security officer will send a generic image (like a non-specific cartoon) to the officers at the scanning site which marks the place on the body where the object has been detected. This ensures that the officers never meet face-to-face with people whose full-body image they have seen.

But just how detailed are the images? They resemble blurred photo negatives, and according to the Department of Homeland Security, ‘do not present sufficient details that the image could be used for personal identification.’ However, the image is detailed enough that the outlines of genitals can be seen in black-and-white.

There have been a number of controversies regarding whole-body imaging, especially over the storing of images. In February 2010, the actor Shahrukh Khan claimed that staff at London’s Heathrow airport circulated a print-out of his scanned image. This was immediately rejected by the airport, which made it clear that the scanner did not even have facilities for printing. It later turned out that the actor had been joking.

More seriously, CNET News reported in August 2010 that the U.S. Marshals Service had saved thousands of images captured from a checkpoint in Florida. They admitted that images had been retained by the machine for ‘testing, training, and evaluation purposes’, but that these images had been stored with filters which protected the identity of the individuals. They also emphasized that scanners fitted in airports are not usually able to capture images.

The official position is clear - only one security officer sees a person’s full-body scan image. Although full-body scanning is hailed as a huge advance in airport security, personal privacy concerns run deeper. For those people who are not comfortable with anyone seeing an image of their body, even if only temporary, that single security officer might be one person too many.

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