A divided federal appeals court ruled today that the government does not need a probable-cause warrant to access mobile-phone subscribers' cell-site information, a decision reversing lower court decisions that said the location data was protected by the Fourth Amendment.

The 2-1 decision by the 5th U.S. Circuit Court of Appeals is the third federal appeals court to decide the privacy issue. Adding to the possibility that the U.S. Supreme Court might take up the topic, New Jersey's high court two weeks ago ruled that warrants were required for the location data.

All the while, two federal appellate courts have now taken the government's position that court warrants are not required for the location data. And a third federal appellate court said judges had the option to demand warrants. All of which means some suspects are being convicted based on locational data of what towers their cellphones are pinging, and others are not, because some courts are requiring warrants.

What's more, the Supreme Court has not ruled on the issue. However, the justices last month rejected an appeal (.pdf) from a drug courier sentenced to 20 years after being nabbed with 1,100 pounds of marijuana in a motor home camper the authorities tracked via his mobile phone pinging cell towers for three days from Arizona to a Texas truck stop.

In that case, the Supreme Court let stand the Ohio-based 6th U.S. Circuit Court of Appeals, which covers Kentucky, Michigan, Ohio and Tennessee. The appeals court ruled that probable-cause warrants were not necessary to obtain cell-site data.

Meanwhile, today's 5th Circuit ruling comes as the authorities have widely adopted using warrantless cell-tower locational tracking of criminal suspects in the wake of the Supreme Court's ruling 18 months ago that they need probable-cause warrants from judges to affix covert GPS devices to vehicles.

The 5th Circuit and 6th Circuit distinguished the case from the GPS case decided by the Supreme Court. The high court ruled that the physical act of installing a GPS device on a target's vehicle amounted to a search, which usually necessitates a probable-cause warrant under the Fourth Amendment.

In the end, the 5th Circuit, which sets law in Louisiana, Mississippi and Texas, concluded today that the locational history of a mobile phone does not enjoy constitutional protections because the government has not performed the tracking, and that the data is simply a business record owned by carriers. (.pdf)

"… cell site information is clearly a business record. The cell service provider collects and stores historical cell site data for its own business purposes, perhaps to monitor or optimize service on its network or to accurately bill its customers for the segments of its network that they use. The Government does not require service providers to record this information or store it. The providers control what they record and how long these records are retained."

The 5th Circuit litigation concerns unidentified drug suspects in which the lower court rulings said "compelled warrantless disclosure of cell site data violates the Fourth Amendment."

The government argued that a mobile-phone company may disclose historical cell-site records created and kept by the company in its ordinary course of business, where such an order is based on a showing of "specific and articulable facts" that there are reasonable grounds to believe that the records sought are relevant and material to an ongoing criminal investigation.

A record number of Americans are embracing mobile phones, which are a de facto style of tracking device consumers willingly place in their pockets and purses. As of December, there were 326.4 million wireless subscriber accounts, exceeding the U.S. population, responsible for 2.3 trillion annual minutes of calls, according to the Wireless Association.

"This ruling fails to recognize that Americans do in fact have a reasonable expectation of privacy in their cell phone location information. Where you go can reveal a great deal about your life, and people don’t think that carrying a cell phone around means that someone can get a detailed record of their movement for days or even months on end," said Catherine Crump, a staff attorney with the American Civil Liberties Union. "The government should not be able to access this personal, sensitive information without getting a warrant based on probable cause. Unfortunately, the Fifth Circuit's decision allows exactly that."

A final case in the federal appellate courts is pending in the 4th U.S. Circuit Court of Appeals, which covers Virginia, West Virginia, North Carolina and South Carolina.

That case concerns a Maryland federal judge declining last year to suppress evidence that Aaron Graham and Eric Jordan were allegedly involved in a string of Baltimore City fast-food restaurant robberies. They were arrested in connection to one robbery, and a 7-month historical look of their phone records – obtained without a warrant – placed them on the scene when other restaurants were robbed, the authorities said.