JUSTICES REIN IN POLICE ON GPS TRACKERS

WASHINGTON--The Supreme Court ruled Monday that police violated the
Constitution when they attached a Global Positioning System tracker to
a suspect's vehicle without a valid search warrant, voting unanimously
in one of the first major cases to test privacy rights in the digital
era.

The decision offered a glimpse of how the court may address the flood
of privacy cases expected in coming years over issues such as
cellphones, email and online documents. But the justices split 5-4
over the reasoning, suggesting that differences remain over how to
apply age-old principles prohibiting "unreasonable searches."

The minority pushed for a more sweeping declaration that installing
the GPS tracker not only trespassed on private property but violated
the suspect's "reasonable expectation of privacy" by monitoring his
movements for a month. The majority said it wasn't necessary to go
that far, because the act of putting the tracker on the car invaded
the suspect's property in the same way that a home search would.

Justice Antonin Scalia, writing for the majority, said that as
conceived in the 18th century, the Fourth Amendment's protection of
"persons, houses, papers, and effects, against unreasonable searches
and seizures" would extend to private property such as an automobile.

"The Government physically occupied private property for the purpose
of obtaining information. We have no doubt that such a physical
intrusion would have been considered a 'search' within the meaning of
the Fourth Amendment when it was adopted," Justice Scalia wrote,
joined by Chief Justice John Roberts and Justices Anthony Kennedy,
Clarence Thomas and Sonia Sotomayor.

Advocates for privacy said that despite the differences, the court's
unanimity on the outcome sent a strong message.

"This is a signal event in Fourth Amendment history," said Walter
Dellinger, a former acting solicitor general who represented the
defendant, Antoine Jones.

The government said Federal Bureau of Investigation agents use GPS
tracking devices in thousands of investigations each year. It argued
that attaching the tiny tracking device to a car's undercarriage was
too trivial a violation of property rights to matter, and that no one
who drove in public streets could expect his movements to go
unmonitored. Police were free to employ the tactic for any reason
without showing probable cause to a magistrate and getting a search
warrant, the government said.

The justices seemed troubled by that position at arguments in
November, where the government acknowledged it would also allow
attaching such trackers to the justices' own cars without obtaining a
warrant.

Emphasizing the Fourth Amendment's "close connection to property,"
Justice Scalia wrote that even a small trespass, if committed in "an
attempt to find something or to obtain information," constituted a
"search" under the Fourth Amendment.

In a surprising departure from the majority, Justice Samuel Alito, a
former prosecutor usually known for his law-and-order views, split
from fellow conservatives to argue that the search violated an
individual's "reasonable expectation of privacy."

The court has used that test since 1967, when it held that warrants
were required before police could wiretap a call made from a public
telephone booth because "the Fourth Amendment protects people, not
places."

Limiting Fourth Amendment protections to trespassing property as
understood in 1791 "is unwise" and "highly artificial," Justice Alito
wrote in a concurring opinion, joined by Justices Ruth Bader Ginsburg,
Stephen Breyer and Elena Kagan. "It is almost impossible to think of
late-18th-century situations" analogous to placing a GPS tracker on a
car, Justice Alito wrote, unless one imagined "a gigantic coach, a
very tiny constable, or both."

With such rapidly advancing technology, the Scalia approach left open
"particularly vexing problems," Justice Alito wrote, particularly when
police don't have to physically touch a vehicle to conduct
surveillance. He mentioned automatic toll-collection systems and
smartphones that continuously track their own location as examples.

Justice Alito's concurring opinion suggested that the GPS case had
provoked a robust debate within the court over the extent to which the
1967 case, Katz v. U.S., remained good law.

Justice Scalia declined to apply the 1967 standard to this case, but
emphasized that the broader approach remained in force.

Justice Scalia wrote that even surveillance without physical trespass
may be "an unconstitutional invasion of privacy"--but, he added, there
was no need to speculate on such problems until a specific case
presented them to the court.

Monday's decision stems from a narcotics operation that turned up
nearly 100 kilograms of cocaine and $1 million when authorities raided
a house in suburban Fort Washington, Md., in 2005.

District of Columbia police and FBI agents watched Mr. Jones, a
nightclub owner, for months with an array of surveillance techniques,
including tapping his cellphone under a warrant from a federal judge.

A federal appeals court in Washington voided Mr. Jones's conviction,
however, because police followed his movements for four weeks by
putting a GPS tracker on his Jeep Grand Cherokee without a valid
warrant. Police had a warrant for the District of Columbia, but it had
expired before the GPS device was installed in Maryland.

In an effort to preserve Mr. Jones's conviction, the government argued
that no warrant was needed in the first place.

Monday, law-enforcement officials said the decision would primarily
affect major narcotics investigations, like that which snared Mr. Jones.

Patricia Lykos, the district attorney in Houston, said police
conducting drug investigations often don't have time to obtain a
warrant before attaching a tracking device.

"When you need a warrant, it's usually like 3 o'clock in the morning,"
she said. "You can imagine the danger that law enforcement is in when
they try to plant one of these devices in the first place."

But Vernon Herron, a former Maryland state police commander, said
investigators rarely have trouble obtaining warrants.

"Courts have been very liberal with allowing the use of these
devices," said Mr. Herron, now a policy analyst with the Center for
Health and Homeland Security at the University of Maryland.

Justice Sotomayor, while joining the Scalia opinion, wrote separately
to set out various privacy issues that emerging technology was
presenting, citing the fact that so many routine actions now are
tracked by private websites.

Court precedents generally provide no protection against third
parties, such as telephone companies, voluntarily turning over
information they collect about an individual to the government. In the
digital age, however, "I for one doubt that people would accept
without complaint the warrantless disclosure to the Government of a
list of every website they had visited in the last week, or month, or
year," she wrote.