Scan this

non-wand terahertz scannerUp-and-coming terahertz scanners would allow security staff to see people as if naked; more up-and-coming yet is a handheld terahertz scanner, which, rather than producing an on-screen image (and maybe making people uncomfortable, what with them being seen au naturel on some security screen for guards to snicker and chuckle at), would simply operate on a red-light/green-light basis: red-light bad, green-light good.

(NewScientist: “Handheld terahertz wand to unmask terrorists,” by Duncan Graham-Rowe [July 12, 2004]; image from Jefferson Lab Free-Electron Laser Program page)