The Transportation Security Administration (TSA) announced yesterday the installation of millimeter wave whole-body scanners at Los Angeles International Airport (LAX) and John F. Kennedy International Airport (JFK).

"The use of whole body imaging is a significant step forward in checkpoint technology," said TSA Administrator Kip Hawley. "By expanding the use of millimeter wave, we are providing our officers with another tool to enhance security and protect the public from evolving threats."

Whole-body scanners use extremely high frequency (EHF), also known as millimeter band or millimeter wave. The frequencies range from 30 to 300 gigahertz. Specific frequency windows can penetrate clothes but bounce off the skin or other dense objects worn under the clothes. This means that the TSA scanners provide the image of a naked body with reasonable detail.

Three security scanners using millimeter waves were put into use at Schiphol Airport in Amsterdam on 15 May 2007, and in the United States there are already such scanners at Phoenix Sky Harbor International Airport.

The Transportation Security Administration announced that at LAX, the scanners will be tested in a random continuous protocol. This means that passengers will be picked at random and forced either through the new scanner or trough a traditional body search, depending on their choice. Special signs will make clear the two choices, even for non-English speaking people.

Security guards will not be able to see the person's face or their identity, as they will be at a remote location. However, they will be able to communicate with the officer on site to transmit whether any security threat was found upon the whole-body scan. The technology uses very low power electromagnetic waves and is harmless to the scanned person, who has to stand still for a few seconds.

"I don't think people are really aware of just how accurate and detailed the images are of their naked body," said Peter Bibring, a staff attorney for the American Civil Liberties Union (ACLU) office in Los Angeles, to the LA Times. "We need to make sure there are good safeguards."