Survival Arts

"Radar Scope sees through walls"

I had an offer to get some free stick time in a friend's friend's luxury (pressurized cabin, an aisle between the seats, etc.) airplane for a trip he and the other guy were making to CES in Las Vegas, but I'm getting ready for school on Monday, so I declined. I'm taking in some of the show's highlights by way of reportage, and just saw this on one of the gadget/gimmick blogs:

"Radar Scope sees through walls"

Fascinating, and a bit terrifying at the same time. It's a handheld device for detecting people on the other side of a (presumably radiolucent) wall. The display device looks milspec/ruggedized, and the printed matter pitches to military application, but I'm quite sure they're being pitched to police departments too. I wonder, what are the relevant U.S. laws with respect to using this device in warrantless searches? I believe SCOTUS has already ruled that "standoff" search techniques are not covered under the 4th Amendment.