SUPREME COURT BARS HIGH-TECH SNOOPING

WASHINGTON, June 11 -- In an important declaration of the constitutional
limits on new privacy-threatening technology, the Supreme Court ruled today
that the use by the police of a thermal imaging device to detect patterns
of heat coming from a private home is a search that requires a warrant.

The court said further that the warrant requirement would apply not only to
the relatively crude device at issue but also to any "more sophisticated
systems" in use or in development that let the police gain knowledge that
in the past would have been impossible without a physical entry into the home.

"We must take the long view, from the original meaning of the Fourth
Amendment forward," Justice Antonin Scalia wrote for a 5-to-4 majority that
cut across the court's usual ideological division. [Excerpts, Page A29.]

Justice Scalia said that to take any other approach "would leave the
homeowner at the mercy of advancing technology -- including imaging
technology that could discern all human activity in the home."

The decision overturned a ruling by the United States Court of Appeals for
the Ninth Circuit in San Francisco — often regarded as the most liberal of
the federal appeals courts -- which held in 1999 that the warrantless use
of a device that revealed patterns of heat suggestive of an indoor
marijuana-growing operation did not violate the Fourth Amendment's
prohibition of unreasonable searches.

In a dissenting opinion today, Justice John Paul Stevens -- who in turn is
usually described as the court's most liberal justice -- said the Ninth
Circuit was correct and that the police activity in the case "did not
invade any constitutionally protected interest in privacy." He said that
for the court today to make a constitutional rule about future technology
was "unnecessary, unwise and inconsistent with the Fourth Amendment."

Those who joined Justice Scalia in the majority were Justices David H.
Souter, Clarence Thomas, Ruth Bader Ginsburg and Stephen G. Breyer. Chief
Justice William H. Rehnquist joined the dissent, as did Justices Sandra Day
O'Connor and Anthony M. Kennedy.

The case, Kyllo v. United States, No. 99-8508, was a federal drug
prosecution that began in 1992, when two federal agents trained a device
called Agema Thermovision 210 on a home in Florence, Ore., where, on the
basis of tips and utility bills, they believed marijuana was being grown
under high-intensity lamps. While the imager cannot see through walls, it
can detect hot spots, and in this case disclosed that part of the roof and
a side wall were warmer than the rest of the building and the neighboring
houses.

The agents used that information to get a warrant to enter and search the
home, where they found more than 100 marijuana plants growing under halide
lights. The resident, Danny Kyllo, entered a conditional guilty plea while
continuing to contest the validity of the search. He served one month in jail.

When Mr. Kyllo's Supreme Court appeal was argued in February, the
government strongly defended use of thermal imagers on the ground that in
detecting heat loss, the devices neither reveal private information nor
violate the "reasonable expectation of privacy" that is the Supreme Court's
test under the Fourth Amendment.

But in the home, Justice Scalia said today "all details are intimate
details, because the entire area is held safe from prying government eyes."
Noting that the court's precedents draw "a firm line at the entrance to the
house," he added, "That line, we think, must be not only firm but also bright."

Despite its forceful language, the decision was undoubtedly not the court's
final word on the subject of privacy and technology. Justice Scalia's
emphasis on the home raised the prospect that warrantless imaging of other
locations might be upheld. And it is far from clear under the court's
precedents that a person in a home that belonged to someone else would have
standing to challenge the use of an imager.

Further, the majority limited its holding to devices that are "not in
general public use," without explaining that limitation. In his dissenting
opinion, Justice Stevens said this limitation was "somewhat perverse
because it seems likely that the threat to privacy will grow, rather than
recede, as the use of intrusive equipment becomes more readily available."

Nonetheless, the decision was important and "surprisingly broad," said
James J. Tomkovicz, a law professor at the University of Iowa who filed a
brief for the National Association of Criminal Defense Lawyers and the
American Civil Liberties Union.

"It was important for the court to say that there are general limits on the
ability of technological developments to erode Fourth Amendment privacy,"
he said in an interview.

The vote today underscored the unpredictable, if not incoherent, nature of
the court's rulings on the Fourth Amendment, currently an extremely active
area of the court's jurisdiction. Last year, for example, the court ruled
that police officers had conducted an unconstitutional search when they
walked down the aisle of a long-distance bus and squeezed passengers'
overhead luggage to look for contraband. Chief Justice Rehnquist wrote the
7-to-2 opinion in that case, Bond v. United States, while Justices Scalia
and Breyer dissented.

On display today was Justice Scalia's insistence that the Fourth Amendment
be interpreted according to the understanding of its framers.

Requiring a warrant to use technology that displaces an old-fashioned
search "assures preservation of that degree of privacy against government
that existed when the Fourth Amendment was adopted," Justice Scalia said.

For Justice Stevens, on the other hand, the problem with the majority
opinion appeared to be its sweeping nature.

In crafting "an all-encompassing rule for the future," Justice Stevens
said, the court "has unfortunately failed to heed the tried and true
counsel of judicial restraint." He added, "It would be far wiser to give
legislators an unimpeded opportunity to grapple with these emerging issues
rather than to shackle them with prematurely devised constitutional
constraints."