EVEN WALLS WON'T PROTECT YOUR PRIVACY NOW

SAN DIEGO In the continuing saga of government invasion of our personal
privacy, today could be a landmark day.

The U.S. Supreme Court will hear arguments in a case that asks whether
police may use "thermal imaging" devices to detect the heat coming from a
house -- in this case, heat from an indoor marijuana-growing operation --
without first obtaining a search warrant. Does this police practice violate
our cherished Fourth Amendment guarantee against "unreasonable searches and
seizures"?

The case is being closely watched as a guide for a whole new generation of
spy toys and detection devices that law enforcement officials are using to
gather evidence against potential lawbreakers.

Today, the issue is thermal imagers, hand-held devices that can detect
small gradients in temperature in the houses, cars and bodies at which they
are pointed. But that is just the beginning, as panelists at an American
Bar Association discussion here Friday made clear.

Not long from now, panelists said, we will be grappling with satellite
imagery, increasingly capable of identifying small objects (marijuana
bales, perhaps stolen cars) from space. The recent use of digital cameras
at the Super Bowl to match attendees with the images of known criminals
opens another new frontier. With the advent of retinal "fingerprinting" --
our retinas are unique -- one scientist in the audience said that someday a
well-placed device could scan the eyes of everyone at a stadium and
precisely identify every individual there.

Some jurisdictions want to place transponders in all vehicles, enabling
police to determine, for example, who passed by or stopped at a crime scene
at a given time. Great for law enforcement, but not so great for our
freedom to travel. Video cameras on street corners and night-vision devices
that can identify a person from a mile away in total darkness are already
in use.

The explosive growth of these devices can be traced to the end of the Cold
War, said panelist Ronald Goldstock, a New York lawyer. National security
agencies that once did not want their surveillance devices scrutinized in
court are now less worried about letting police use and defend the technology.

Now is the time to intensify the study of "the application of the
Constitution to significant new forms of technology," said Washington,
D.C., lawyer Sheldon Krantz at the San Diego discussion.

The case before the Supreme Court is a good place to start. More than nine
years ago, Oregon law enforcement officers used a thermal imaging device --
an AGEMA Thermovision 210, to be exact -- to determine that a lot of heat
was emanating from the roof and one wall of a house on Rhododendron Drive
in Florence, Ore. As they suspected, Danny Kyllo, the occupant of the
house, was not growing rhododendrons or even African violets inside the
house, but rather marijuana.

Kyllo was arrested on marijuana-manufacturing charges in January 1992. Ever
since, the courts have wrestled with whether the use of the device by
police violated Kyllo's Fourth Amendment rights.

As that length of time suggests, these issues are not easy. In this case
and others that have looked at thermal imaging, judges cannot even agree
about what is being searched by these devices. Some, including the latest
ruling in the Kyllo case, say the police are only capturing "heat waste"
outside the house and not searching or piercing the privacy of the house at
all. Some have analogized this "heat waste" to the garbage you put at the
side of the road for collection -- which the Supreme Court has already said
can be searched by police without a warrant.

That strained logic has been rejected by other courts that correctly see
the use of these devices as a search of the home itself, not just its
emanations. These thermal devices pick up not only "heat waste" outside,
but also can detect legitimate uses within, such as a hot tub or, as one
court artfully put it, "two commingled objects emitting heat in a bedroom
at night" through an open window. What happened to Kyllo was clearly a
search that should have been subject to Fourth Amendment constraints.

Ever since the Supreme Court first grappled with the Fourth Amendment
implications of wiretapping technology early in the past century, a major
factor it considers is whether the police activity violates what society
would regard as a reasonable expectation of privacy. By now, for example,
we no longer have a reasonable expectation that the contents of our luggage
will be private when we head to the airport. As a result, officials there
can pass our bags through a metal detector without first obtaining a search
warrant.

With thermal imaging, as with the other new surveillance devices, that
expectation of privacy needs to be preserved in the law early in the life
of the technology. Once a new method of invading privacy becomes
commonplace, in an oddly self-fulfilling way, it is hard to stop, because
the public's expectation of privacy from the device has been washed away.

The case of Danny Kyllo may be the last best chance for the Supreme Court
to draw the line boldly in favor of privacy and to keep our homes, at
least, secure from the Orwellian future of a heat-seeking,
eyeball-scanning, omnipresent government.