I can't understand what people are frightened of. The scan only shows some vague body contours, as does the manual "pat down". Surely this device is preferable to any previous method of detecting weapons?
As I have a manual "pat down" every time I go through security, I'd be perfectly happy to submit to a "low-level x-ray". The security people already know how fat/thin I look by my clothing, so they certainly don't need to confirm it by X-ray!!