Telephone numbers connected to specific cell phone towers can be gathered by the government from telecommunications companies under the Stored Communications Act, a federal judge has ruled.

Southern District Magistrate Judge James Francis (See Profile) said Friday that so-called “cell tower dumps” do not violate the Fourth Amendment’s prohibition on unreasonable searches and seizures and do not require a warrant under the act.

Francis’ order gives the government freedom to collect cell phone tower information over a 4 1/2 hour period from Verizon Wireless, AT&T and other companies—information a prosecutor told the judge would help establish “that the listed cellular telephones were somewhere in the vicinity of that particular cell tower during that time period.”

The cell numbers, Francis said in his opinion, would be compared with similar information “to determine numbers that were used at multiple locations, as well as numbers that match those that law enforcement has learned are associated with certain persons under investigation for the series of crimes at issue.”

Francis solicited the views of the American Civil Liberties Union and the New York Civil Liberties Union as amicus curiae in the case: In The Matter of the Application of the United States of America for an Order Pursuant to 18 U.S.C. §§2703(c) and §§2703(d) Directing AT&T, Sprint/Nextel, T-Mobile, Metro PCS and Verizon Wireless to Disclose Cell Tower Log Information.

Section 2701(c) of the act allows the government to obtain an order directing any provider of an electronic communication service to release the records of “a subscriber or customer of such service” when the government presents “specific and articulable facts showing that there are reasonable grounds to believe” the records “are relevant and material to an ongoing criminal investigation.”

The ACLU and NYCLU argued unsuccessfully that Congress intended the phrase “a subscriber or customer” to be read in the singular.

But even if the act does not prohibit cell tower dumps, the groups argued that the government could not obtain the records under §2701(d) “because it seeks vast quantities of irrelevant and immaterial—yet extraordinarily sensitive—information about hundreds of thousands of innocent parties.”

They claimed an order directing the production of the material would violate the Fourth Amendment because there was a lack of reasonable suspicion that all the people whose records were obtained were engaged in criminal activity.

But Francis said reasonable suspicion is not the standard under the act. He then turned to the Fourth Amendment’s warrant requirement, an analysis that includes whether a person has a subjective expectation of privacy and whether that expectation is reasonable.

The civil liberties groups had contended the cell tower dumps amounted to arguably unconstitutional “dragnet-type” surveillance, but Francis was not persuaded.

“Rather, the government seeks to retrieve phone numbers used during a particular time period in a particular area to be cross-referenced with data generated from other areas relevant to the investigation during other relevant time periods,” he said. “There is no possibility that widespread tracking of the locations of individuals could ensue if the application is granted.”

Francis then discussed the “voluntary disclosure doctrine,” also known as the third-party disclosure doctrine, which holds that disclosures made by people voluntarily do not fall “within a protected zone of privacy.’ United States v. Miller, 425 U.S. 435 (1976).

Miller concerned bank records, but the Supreme Court extended the logic of Miller three years later in Smith v. Maryland, 442 U.S. 735 (1979), holding that the use of a pen register, which records the numbers dialed, does not constitute a “search” under the Fourth Amendment because phone users know phone companies are recording the information for a number of legitimate business reasons.

“I agree that Smith and Miller dictate the outcome here, where the subscribers are aware that use of their cell phones necessitates disclosure of the information sought,” Francis said.

Calls Made From ‘Home’

The civil liberties groups also argued that many of the calls the government wants were made in the “constitutionally protected spaces” of peoples’ homes. They said the U.S. Supreme Court has insisted that searches and seizures within a home without a warrant are presumptively unreasonable.

To that end, Francis said, the high court has said law enforcement monitoring of a beeper on a can of ether inside a home required a warrant, as did the use of a thermal-imaging device aimed a private home.

But he added, “As Smith makes clear, the voluntary disclosure doctrine applies even where the disclosures are made from the protected space of a home.”

The ACLU and NYLCU said it was within the court’s discretion to apply a higher standard in deciding whether to issue the order.

While Francis said certain searches by the government of voluntarily disclosed information “may be so invasive that it would be prudent to require a showing of probable cause,” he would not require a warrant in this case “because the telephone numbers associated with the communications in a general location” do not “implicate privacy interests to the same degree as, for example, the content of those communications.”

Nevertheless, Francis said he was requiring the government to submit an amended application that “(1) provides more specific justification for the time period for which the records will be gathered and (2) outlines a protocol to address how the Government will handle the private information of innocent third-parties whose data is retrieved.”

Assistant U.S. Attorney Jason Masimore represented the United States.

The amicus brief was submitted by Nathan Freed Wessler, Brett Max Kaufman, Alex Abdo, Ben Wizner and Catherine Crump of the American Civil Liberties Union and Christopher Dunn and Arthur Eisenberg of the New York Civil Liberties Union.

“Though appreciative of being able to weigh in on the legality of these highly invasive tower dumps, we disagree with much of the court’s reasoning. Nonetheless, its decision to demand more of the government is a step forward, as courts should at the very least limit their use to protect the privacy of the countless innocent individuals affected,” Wessler said.