An anonymous reader quotes the BBC:
Ordinary wi-fi could be used to detect weapons and explosives in public places, according to a study led by the Rutgers University in New Jersey. Wireless signals can penetrate bags to measure the dimensions of metal objects or estimate the volume of liquids, researchers claim. Initial tests appeared to show that the system was at least 95% accurate. It could provide a low-cost alternative to airport-style security, researchers said. The system works by analysing what happens when wireless signals penetrate and bounce off objects and materials.
of this story at Slashdot.
Source:: Slashdot