X-RAY VISION, A SURPRISING SUPREME COURT RULING SHEDS
LIGHT-AND OTHER BEAMS-ON THE LATEST SNOOPING TECHNOLOGY

The technology that the nine justices of the Supreme Court wrestled
with last week was relatively crude: a heat-sensing gun pointed at a
house in Florence, Ore., by federal agents on the lookout for
homegrown marijuana. In 1992, a cop using the device had spotted a lot
of excess heat coming off high-intensity grow lights. Police searched
the house, found more than 100 plants and arrested one of its
occupants--a small-time marijuana grower named Danny Kyllo. Kyllo
appealed the case all the way to the highest court, arguing that by
using infrared technology to pry into his home, the government had
conducted an unconstitutional search.

To the surprise of many court watchers, the majority ruled in Kyllo's
favor. And the dissenting Justices in the 5-4 decision made it clear
that even if they were willing to accept "off-the-wall" technologies
like infrared guns--which can pick up signals only from the outside of
a building--they viewed with alarm newer "through-the-wall" devices
that can see inside.

Through the wall? Yes, indeed. A whole new generation of surveillance
technology has been developed since Kyllo was busted. Some of these
new devices are already turning up at airports, prisons, border
crossings and crime scenes. And while none of them is quite up to the
standards of, say, Superman, they can see through clothing and peer
into private homes well enough to raise thorny privacy issues for all
of us. Among the leading contenders:

X-RAY VISION Today's preferred technology for looking through things
is the same one Wilhelm Roentgen used to photograph the bones in his
wife's hand in 1895, although the newest X-ray devices are
considerably more powerful. Last September, for example, the U.S.
Customs Service placed an order worth more than $ 25 million for 15
truck-based X-ray inspection systems made by American Science and
Engineering, Inc., in Billerica, Mass. Using a technique in which
images are made from X rays scattered back from objects (rather than
passing through them), AS&E's systems can spot--with extraordinary
clarity--guns, drugs, plastic explosives and other contraband, even
when hidden, say, in the middle of a fully packed banana truck. One of
the company's products, called BodySearch, reveals ghostly images of
weapons and whatever else--including genitals--might be hidden
underneath your clothes.

RADAR FLASHLIGHTS Gene Greneker, a radar expert at Georgia Tech, was
fiddling with a radar gun he had developed for monitoring marksmen and
archers during the 1996 Atlanta Olympics when he noticed something
odd: whenever someone walked on the other side of his laboratory wall,
a deflection appeared on the radar screen. One thing led to another,
and now Greneker is trying to smooth out the final kinks in his Radar
Flashlight, a device that looks like an oversize hair dryer but can
penetrate 8-in.-thick nonmetal doors and walls. When radar waves
encounter moving objects, like a hostage taker's nervous pacing or
heaving diaphragm, the motions are translated into a bar of LED lights
in which the height of the bar corresponds with the amount of movement
in the room. In more sophisticated radar detectors, like the prototype
made by Time Domain Corporation of Huntsville, Ala., the crude LED
display is replaced by dancing circles and colored blobs that show
both the location and trajectory of moving objects on the other side
of an opaque barrier.

BEYOND BAR GRAPHS Some firms are pushing for yet more clarity. Using
shorter-wavelength radar waves measured in millimeters, not
centimeters, Millivision in Amherst, Mass., makes a device that goes
well beyond colored blobs. "What we are doing is real imaging," says
Richard Huguenin, chief technology officer. "You see a picture."
Actually, it's more like a shadow. The human body, as it turns out,
naturally emits millimeter radiation that goes right through clothes.
So anything blocking that emission, such as a concealed gun or wallet,
shows up as a shadow in the images produced by Millivision's prototype
scanners. Huguenin acknowledges the privacy concerns, but he argues
that the technology's public-safety benefits outweigh them. "You can
tell the boys from the girls" with his device, says Huguenin, "but you
usually can anyway."

The Supreme Court was clearly more troubled by the privacy issues than
Huguenin. The majority opinion explicitly used the heat-detector case
to draw what Justice Antonin Scalia called a firm, bright line
blocking the use of this and future imaging technologies to peer into
the home or any other place where an individual might have a
reasonable expectation of privacy.

But the court also left the police a couple of outs. The first is to
get a search warrant. If the cops have good reason to peer inside a
house, they can always go to a judge and get permission--just as they
do today with a wiretap. The second is to wait for the technology to
become ubiquitous. If everybody owns a through-the-wall imager, the
court suggested last week, then nobody can reasonably expect any
privacy anywhere, even at home.