A federal judge in the Western District of Pennsylvania has ruled that the government must procure a search warrant before covertly obtaining information about cell phone users’ geographic location from their wireless service providers.

The ruling perpetuates a continued split on this issue, with several courts concurring with this decision, while other federal courts have found that a warrant is not necessary under similar circumstances. The issue is not yet resolved, and may need to be addressed by appellate courts in order to get consensus.

The opinion issued on September 10, 2008, upheld a more extensive February 2008 federal magistrate’s ruling. That magistrate’s decision required the government to show probable cause when seeking a court order that would compel a wireless provider to turn over location tracking information without the subscriber’s knowledge or consent.

The key issue in such cases is the need for law enforcement to satisfy the Fourth Amendment’s probable cause standard. As the Pennsylvania magistrate stressed, “the issue is not whether the Government can obtain movement/location information, but only the standard it must meet to obtain a Court Order for such disclosure.”

The Department of Justice argued that the Stored Communications Act (SCA), 18 U.S.C. § 2703, authorizes a wireless carrier to provide detailed location information obtained by tracking the specific cell tower sites with which a subscriber’s mobile device communicates. The government sought the information in this instance to follow the movements of a suspected drug trafficker, relying on language in the statute that allows a court to issue an order on a showing of “specific and articulable facts” demonstrating reasonable grounds to think that user records or “other information” may be relevant and material in an ongoing criminal investigation.

The Pennsylvania magistrate’s decision rested on the Fourth Amendment and several statutory grounds, finding in particular that the SCA excluded “tracking device” communications from the law’s definition of the information that the government may obtain under this statute. Courts in other districts have reached the opposite conclusion.

For example, a 2006 decision in the Southern District of Texas determined that no warrant was necessary, so long as the government sought cell-site information obtained during calls made by or to the subscriber, but did not seek information (such as GPS signals) that could be used to track the location of the phone when no call was in progress. A 2007 Massachusetts federal court decision held that the government could obtain historical cell-site data without a warrant, but distinguished historical records from real-time information that could be used to track a cell phone user’s present whereabouts.

Despite these contrary outcomes, the Pennsylvania decision falls in line with federal court decisions denying government requests in the District of Columbia, Indiana, Maryland, New York, and Wisconsin. In the Pennsylvania case, the magistrate decided that the government should not have the benefit of the relatively lenient “specific and articulable facts” standard, as probable cause jurisprudence “require[s] only that the Government support its belief of criminal activity and the probable materiality of the information to be obtained.”

The order expressed concern that, absent such a showing, governmental abuse could occur because of the ex parte nature of warrantless requests, the low cost of obtaining the information, and the undetectable nature of the process used to transfer information to the requesting authorities.

While acknowledging the “important and sometimes critical crime prevention and law enforcement value of tracking suspected criminals,” the Pennsylvania magistrate concluded that the value of warrantless access to this information was outweighed by the need for more stringent judicial review to protect civil liberties such as the rights of privacy and free association. The magistrate focused on the need to protect “extraordinarily personal and potentially sensitive” location information that is frequently and broadly sought by the government, but without subscriber consent.

Another interesting point of comparison, beyond the different outcomes in the U.S. court system, is the treatment of cell phone users’ geographic location information under European Union privacy directives. For example, in electronic communications and personal privacy standards adopted as early as 2002, the EU generally has prohibited the collection and processing of location data without the explicit consent of the mobile device user. Nevertheless, these same EU standards permit member states to restrict such privacy rights when necessary to trace nuisance calls or to provide emergency services.

No matter the resolution of the split between U.S. courts, wireless providers can expect to continue receiving court orders requiring them to provide cell phone location information without subscriber consent. If higher courts ultimately determine that warrants are necessary in such instances, however, that decision could reduce the government’s willingness or ability to make requests as frequently.


The Western District of Pennsylvania's September 10th opinion may be reviewed here via a link supplied by the Electronic Frontier Foundation (EFF).

The magistrate judge's February 2008 ruling may be accessed here via an EFF link.

The EU Directive may be accessed here.