Minneapolis-St. Paul International Airport has begun using millimeter-wavelength full body scanners at one of its checkpoints. The scanners use radio waves to create an image of a person's body. The waves pass through clothing but can detect metallic and no-metallic items hidden under clothing. These types of scanners have raised privacy concerns, as they can create a detailed (although somewhat blurry) picture of a person's body. The airport hopes to get additional scanners in place this Fall.
Source: Planet Data