A new full-body scanner being tested by the U.S. government as a replacement for airport metal detectors can see through the clothing of passengers.

For the U.S. Transportation Security Administration (TSA), it's the latest step to wipe out terrorism.

The "millimeter wave scanner" is meant as a secondary screening of passengers pulled out of the security line, and can be requested instead of the traditional pat-down.

The machine uses radio waves to detect foreign objects and scans the entire body at high speed.

Because it produces such a detailed image, technology and privacy experts at the American Civil Liberties Union feel use of the machine is a violation of people's privacy.

"It's a virtual strip search," said Melissa Ngo, a director at the Electronic Privacy Information Center. "(It's) a detailed image of a person's body. So detailed that you can see genitalia."

The device is programmed to blur the passenger's face