Naked at the airport
Did you know that the U.S. Department of Homeland Security started testing a security scanner last month at the international airport in Phoenix, Arizona that enables Security to see you naked?
According to the article “New Security Scanner Sees Through Clothes, But With Modesty“:
The backscatter machines bounce low-intensity x-ray beams off skin to create black-and-white images that render clothing transparent. Concealed weapons like ceramic knives and pistols are completely revealed.
But so are intimate body parts.
In U.S. congressional testimony last year, the American Civil Liberties Union called the backscatter technology a “tremendous invasion of privacy” that could reveal personal details like evidence of a mastectomy or genital size.
I’m not sure about you, but THAT just FREAKS ME OUT! 
Anyway, the actual reason for the National Geographic article is to point out that there’s another security scanner that’s being developed that can see through clothes, but rather than give a detailed picture of your body, it generates a heat map of your body, so anything not the same temperature as your body will show up. But, it also manages to identify different materials, so a gun that is now body temperature will also show up as a different colour to that of your body.
Instead of bouncing x-rays off an object to create an image, the sensor Helistö described simply absorbs natural thermal radiation.
The device is sensitive to terahertz frequencies—electromagnetic radiation from between the infrared spectrum and radio spectrum.
The absorbed radiation allows the sensor to map the temperature profile of a body, similarly to a thermal infrared image, Helistö explained.
“The good point of terahertz is that it penetrates most clothing material,” he said.
Since the device is also sensitive to the differing properties of materials, a metal object—even if it is the same temperature as the body—will show up in the image, Helistö added.
Sounds good. Though I’ll bet there are going to be a few upset airport security guards when they find out they don’t get to scan any Playboy Models with the backscatter machines… 
