A VICTORY FOR PRIVACY

Justice Antonin Scalia is not ordinarily celebrated by liberals for his
devotion to the right to privacy. But last week, he wrote a Supreme
Court opinion that is an occasion for all friends of privacy to dance in
the streets. In Kyllo vs. U.S., Justice Scalia held that the government
acted unreasonably when it aimed a thermal imaging device at a suspect's
house and surmised, from the high levels of heat on the exterior walls,
that he was using heat lamps to grow marijuana inside. For a 5-4
majority, Justice Scalia declared that when government agents use
surveillance technology that isn't ordinarily used by the general public
to explore details of the home, the surveillance is presumptively
unreasonable without a search warrant.

Justice Scalia's opinion is only the latest illustration of how privacy
is an issue about which liberal and conservative justices can
increasingly agree. And it provides a model of how the original
understanding of the Constitution can be intelligently translated to
regulate electronic surveillance.

This is a problem that that the court struggled with unsuccessfully for
most of the 20th century. The court's first encounter with electronic
searches was a 1928 case in which the government was using wiretaps to
investigate a suspect bootlegger named Olmstead. Olmstead claimed that
the wiretap violated the Fourth Amendment, which protects the right of
the people to be secure in their "persons, houses, papers, and effects."
But Chief Justice William Howard Taft disagreed. The Fourth Amendment,
he said, was originally understood to forbid only searches or seizures
accompanied by a physical trespass on private property, and the agents
hadn't trespassed on Olmstead's property when they placed wiretaps on
the phone lines in the streets near his house.

In a visionary dissenting opinion, Justice Louis Brandeis noted that
when the Constitution was adopted, breaking and entering into the home
was the only way for the government to invade a citizen's private
thoughts. But in the 1920s, subtler ways of invading privacy, such as
wiretapping, made it possible for the government to invade the privacy
of the home without a physical trespass. To protect the same amount of
privacy that the framers of the Fourth and Fifth Amendments intended to
protect, Brandeis concluded, it was necessary to prohibit unreasonable
searches and seizures of conversations over the wires, even if the
invasions occurred without physical trespass.

In 1967, the Supreme Court appeared to accept Brandeis's argument that
technologically enhanced surveillance could qualify as an unreasonable
search, but it did so in a way that inadvertently undermined Brandeis's
central insight. In the Katz case, government agents attached a
listening device to a public telephone booth and recorded a suspect's
end of the conversation without his knowledge. Overruling the Olmstead
decision, the court announced that the "Fourth Amendment protects
people, not places."

In an influential concurring opinion, Justice John Harlan proposed the
following test for determining what kind of surveillance activity should
trigger the protections of the Fourth Amendment: A person must have an
actual or subjective expectation of privacy, Harlan suggested, and the
expectation must be one that society is prepared to accept as reasonable

Harlan's test was applauded as a victory for privacy, but it soon became
clear that it was entirely circular. People's subjective expectations of
privacy tend to reflect the amount of privacy they experience; and as
surveillance technologies grew increasingly intrusive, expectations of
privacy were correspondingly diminished. In the 1980s, for example, the
Supreme Court upheld the aerial surveillance of a fenced-in backyard
without requiring a warrant. Since any member of the public could,
hypothetically, rent a helicopter and hover over a neighbor's backyard,
the court suggested, all of us have to assume the risk that the police
might do so, too.

Using the same circular logic in his dissenting opinion in the Kyllo
case, Justice John Paul Stevens would have approved the use of the
thermal imaging devices. Since we voluntary put out heat waves in the
same way that we put out the trash, Justice Stevens suggested, we can't
legitimately expect that our heat waves won't be monitored by what he
aptly called "off the wall" heat-seeking devices.

But in his majority opinion, Justice Scalia rejected this implausible
logic. "The question we confront today is what limits there are upon
this power of technology to shrink the realm of guaranteed privacy,"
Justice Scalia wrote. Far from revealing only public information, the
heat sensors might disclose intimate details of the home, such as "at
what hour each night the lady of the house takes her daily sauna and
bath." To protect the same amount of privacy in the 21st century that
citizens in the 18th century took for granted, Justice Scalia held the
government should get a warrant before using cutting-edge technology to
obtain information about the interior of a home that, 200 years ago,
would have required a physical intrusion.

Justice Scalia has been a consistent defender of the privacy of the home
- -- refusing to allow the police to move a stereo to observe its serial
number, for example. But he is not the only conservative justice devoted
to privacy. Justice Clarence Thomas is the leading advocate for the
privacy of private papers: In the case last year that rejected Ken
Starr's decision to subpoena Webster Hubbell's tax records after
granting him immunity, Justice Thomas wrote a bold concurring opinion
arguing that the Fifth Amendment should protect the content of private
papers, as it was originally understood to do.

Justice Anthony Kennedy is especially concerned about people's privacy
in their cars -- perhaps because of his upbringing in California. And
Justice Sandra Day O'Connor recently wrote a powerful dissenting opinion
in which she argued that the Fourth Amendment should prohibit arrests
for low-level misdemeanors, such as seat-belt offenses, that are
ordinarily punished only by a fine. In all these cases, conservatives
and liberal justices have joined in unexpected alliances, proving that
on the Supreme Court, as on Capitol Hill, privacy is a cross-cutting,
bipartisan issue.

The Kyllo opinion is only the beginning of the court's efforts to
translate the Constitution into a technological age. Justice Scalia held
that surveillance of the home requires a warrant only when the
technology is not generally in public use. As invasive technologies
become more commonplace, the court may have to decide that there are
certain invasions no citizen in a civilized society should endure,
regardless of whether expectations of privacy have been diminished by
technology. And Justice Scalia's opinion is limited to the home, leaving
us vulnerable to the kind of surveillance in public places that
spectators at the Tampa Super Bowl recently experienced: Their faces
were scanned as they entered the stadium and compared with databases of
suspected wrongdoers.

But although Kyllo is only a first step in successfully translating the
original understanding of the Constitution into the electronic age, it
is welcome and long overdue. For this, we have Justice Scalia to thank.