New Airport X-ray Scanning Technology

At Phoenix's Sky Harbor Airport, the newest a weapon in the war on terror can see through clothes carrying explosives. Already used on more than a million passengers abroad, these special X-rays can catch all kinds of contraband.

"Regular weapons: guns, knives, boxcutters, and the like, but also unusual types of weapons: explosives, liquid explosives, gels," said Rapiscan Systems' Peter Kant about the items that can be detected.

The images will look like outlines of the body, not in detail, but weapons and other items do show up. This technology has been very controversial because until recently it was much more invasive.

In August 2006, if someone went through a so-called "back-scatter" machine they would be advised if they didn't want their private areas shown they should put a metal plate in their pants. After being advised, one would step just in front of the machine, turn around and in just a few seconds, the monitor displayed all their humble contours.

Now in tests, where a would-be terrorist is portrayed, a plastic lipstick-container was hidden in a vest-pocket, busted. Next, sports-drink bottle, busted again. How about wires, in a sealed sandwich-bag, hidden in a sock? On the monitor, they show up on the ankle, but the machines have limitations.

When water was poured into a sealed sandwich-bag and placed inside the beltline and in a sock, one can barely see it. But according to the company behind this technology trained screeners would detect it. And the Transportation Security Administration said they have other methods to detect liquids.

When the "back-scatter" machine came out, privacy advocates called it a virtual strip-search, and they're not much more satisfied with the newer X-ray technology.

"Essentially they're putting a digital fig-leaf on the image. This protects the image from what the operator will see. But the machine itself can still record all the detail and store that information for use at a later point," said Marc Rotenberg of Electronic Privacy Info Center.

An TSA official told CNN there won't be any hard-drives to store the images, and said no one will have access to pictures without the so-called "fig-leaf" on them.

An official with the TSA in Phoenix said, the machine will only be used if more than a metal detector is required. Passengers then will get a choice between the new machines and patdowns.