Even many who cherish the “original meaning” of the Constitution recognize that provisions drafted in the 18th century must be interpreted in light of changing technology.

That is especially true of the 4th Amendment’s guarantee of the “right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.”

When the amendment was adopted, unreasonable searches involved physical trespass. In 1967, however, the court ruled that the 4th Amendment was violated when federal agents affixed a wiretap to the outside of a telephone booth being used by a gambler.

What mattered, wrote Justice John Marshall Harlan, was whether the suspect had a reasonable expectation of privacy.

Flash forward to 2001, when the court held that police violated the rights of a drug suspect when they aimed a thermal imaging device at his house to determine whether the heat inside was consistent with marijuana cultivation.

Justice Antonin Scalia wrote: “Where, as here, the government uses a device that is not in general public use, to explore details of the home that would previously have been unknowable without physical intrusion, the surveillance is a ‘search’ and is presumptively unreasonable without a warrant.”

The latest controversy over adapting the privacy protections of the 4th Amendment to new realities concerns global positioning system, or GPS, devices, until recently an exotic technology but now as ubiquitous as the cellphones of which they are a prized feature.

Seven months after the Supreme Court sidestepped a major decision on the constitutionality of warrantless GPS tracking of criminal suspects, a federal appeals court in Cincinnati has issued a decision about the subject that seems as antiquated as a rotary phone.

Melvin “Big Foot” Skinner was a drug runner who was apprehended after Drug Enforcement Administration agents established his location through signals sent by his pay-as-you-go cellphone.

The agents could have sought a warrant for the information by showing probable cause that Skinner was involved in drug trafficking, but instead they obtained an order by convincing a magistrate judge that the desired data were merely “relevant and material to an ongoing criminal investigation.”

Writing for the court, Judge John M. Rogers dismissively observed: “When criminals use modern technological devices to carry out criminal acts and to reduce the possibility of detection, they can hardly complain when the police take advantage of the inherent characteristics of those very devices to catch them.”

Perhaps not, but the 4th Amendment and the requirement of probable cause are designed to protect innocents as well.

Rogers’ decision reflects two legal principles that have been undermined by technological changes. The first is that although the contents of a phone conversation may be protected from casual police intrusion, phone records are not.

In the era of land lines, the courts concluded that callers didn’t anticipate that the exchanges they dialed to and from would be kept secret. In the cellphone era, however, those records can pinpoint not just who called whom but also the phone’s variable location.

The decision also is consistent with a distinction the Supreme Court has drawn between papers in the sole possession of a citizen, and bank and phone records that are the legal property of a corporation. That difference, however, is also an anachronism.

Justice Sonia Sotomayor suggested as much earlier this year in a concurring opinion when the court held that the surreptitious attachment of a GPS device to a drug dealer’s vehicle was a “search” under the 4th Amendment.

It may be necessary, Sotomayor wrote, “to reconsider the premise that an individual has no reasonable expectation of privacy in information voluntarily disclosed to third parties. This approach is ill suited to the digital age, in which people reveal a great deal of information about themselves to third parties in the course of carrying out mundane tasks.”

The framers of the Constitution could not have envisioned the cellphone, much less its ability to establish the whereabouts of its owner, but the language of the 4th Amendment to protect persons and “effects” will, as it so often has, adapt to modern life.

Editorial by the Los Angeles Times

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.