[NonValueAdded]

Besides the obvious invasion of privacy issue here, what is the potential health threat to the public if this is happening?

Exactly! Do we need to wear dosimeters now? Or more importantly, lead-lined codpieces?

[Hodar]

It appears to be the microwave based technology. The radio-activity you are thinking about (X-rays) would require a emitter on the other side of the subject.

This simply looks through the first couple layers of the subject. Depending upon the energy behind the waves, these are no more harmful than your cell phone, calculator, laptop, PC, FM radio or high voltage transmission lines that criss-cross our country delivering power to every home in the USA.