Justice Dept. defends warrantless cell phone tracking

The FBI and other police agencies don't need to obtain a search warrant to learn the locations of Americans' cell phones, the U.S. Department of Justice told a federal appeals court in Philadelphia on Friday.

A Justice Department attorney told the Third Circuit Court of Appeals that there is no constitutional problem with obtaining records from cellular providers that can reveal the approximate locations of handheld and mobile devices. (See CNET's previous article.)

There "is no constitutional bar" to acquiring "routine business records held by a communications service provider," said Mark Eckenwiler, a senior attorney in the criminal division of the Justice Department. He added, "The government is not required to use a warrant when it uses a tracking device."

This is the first federal appeals court to address warrantless location tracking, which raises novel issues of government surveillance and whether Americans have a reasonable expectation of privacy in their--or at least their cell phones' --whereabouts.

Judge Dolores Sloviter sharply questioned Eckenwiler, saying that location data can reveal whether people "have been at a protest, or at a meeting, or at a political meeting" and that rogue governments could misuse that information. (See transcript excerpts below.)

Just a few years ago, tracking phones was the stuff of thrillers like "Enemy of the State" or "Live Free or Die Hard." Now, even though police are tapping into the locations of mobile phones thousands of times a year, the legal ground rules remain unclear, and federal privacy laws written a generation ago are ambiguous at best.

"When the government acquires historical cell location information, it effectively commandeers our cell phones and turns them into electronic trackers that report, without our knowledge or consent, where we have been and how long we have spent there," Susan Freiwald, a law professor at the University of San Francisco, told the court on Friday. "We should be able to use our cell phones without them creating a virtual map of our every movement and association."

Freiwald, the ACLU, the Electronic Frontier Foundation, and the Center for Democracy and Technology filed briefs saying that the U.S. Constitution's Fourth Amendment provides Americans with at least some privacy protections that shield their whereabouts from police not armed with search warrants. The civil liberties groups also said that current law gives judges the flexibility to require search warrants based on probable cause.

EFF attorney Jennifer Granick said one possibility is for the Third Circuit to order the district judge to hold hearings to learn the more about the technology of cell tracking, including how accurately stored records can pinpoint the location of a phone. The judges "had a lot of factual questions about accuracy that haven't been answered," Granick said after the hearing.

Besides Sloviter, the other judges on the panel are Atsushi Tashima, who is visiting from the Ninth Circuit, and Jane Roth, who was not present on Friday but is expected to review the transcript.

The Bureau of Alcohol, Tobacco, Firearms and Explosives is asking the court for an order divulging historical (meaning stored, not future) phone location information because a set of suspects "use their wireless telephones to arrange meetings and transactions in furtherance of their drug trafficking activities." It's unclear how detailed this stored information is; there's some evidence that the FBI can use it to narrow down the location to a city block but perhaps not an individual house.

The Obama administration argues that no search warrant is necessary; it says what's needed is only a 2703(d) order, which requires law enforcement to show that the records are "relevant and material to an ongoing criminal investigation." Because that standard is easier to meet than that of a search warrant, it is less privacy-protective.

Cell phone tracking comes in two forms: police obtaining retrospective historical data kept by mobile providers for their own billing purposes that is typically not very detailed, or prospective tracking--which CNET was the first to report in a 2005 article--that reveals the minute-by-minute location of a handset or mobile device.

Tracking cell phones can be useful for law enforcement. Agents from the Drug Enforcement Administration in Arizona tracked a tractor trailer with a drug shipment through a GPS-equipped Nextel phone owned by the suspect. Texas DEA agents have used cell site information in real time to locate a Chrysler 300M driving from Rio Grande City to a ranch about 50 miles away. Verizon Wireless and T-Mobile logs showing the location of mobile phones at the time calls were placed became evidence in a Los Angeles murder trial.

The civil liberties say they're not opposed to the government obtaining that information for legitimate purposes -- as long as the Fourth Amendment and federal privacy laws are being followed. This is, said Freiwald "a truly novel technology that can invade the privacy of all Americans who carry cell phones in their pockets or purses."

Justice Department's Eckenwiler: That is what has come to be known in the vernacular as triangulation, where various measurements have been made from the towers in proximity to the phone to calculate a rough position to the phone?

Judge Sloviter: How close can you get ?

Eckenwiler: Well, what the regulations require is 50 meters of precision for a handset solution, essentially for all cases, 95 percent, it needs to be accurate within 150 meters... But that's a class of information that's separate and apart from what the government has requested here.

Sloviter: But can you get it? Does the statute permit it? Irrespective of what the government has asked for here, does the statute permit the government to request -- and according to the government to demand, if they make the requisite showing -- information that would let them know where the cell phone user is within 150 meters?

Eckenwiler: As to historical records, your honor.

Sloviter: Yes

Eckenwiler: The answer is if the carriers retain such information, yes, it would allow--

Sloviter: Suppose the information is last week?

Eckenwiler: The statute would allow the government to obtain that information.

Sloviter: There are governments in the world that would like to know where some of their people are, or have been. For example, have been at what may be happening today in Iran, have been at a protest, or at a meeting, or at a political meeting. Now, can the government assure us that -- one, it will never try to find out that information, and two, whether that information would not be covered by (d). [Ed. Note: Sloviter seems to be referring to a 2703(d) order.]

Eckenwiler: Your honor, I can't speak to future hypotheticals in terms of what might happen.

Sloviter: But don't we have to be concerned about that? If the statute would permit the government -- not this government right now but a government -- to get information as to where... Wouldn't the government -- a government -- find it useful if it could get that information without showing probable cause?

Eckenwiler: Your honor, the information at issue in this case certainly is useful, that's why the government's applying for it here.

Sloviter: But without showing probable cause. Because it's relevant. Your papers admit that the showing that needs to be made for a subsection (d) order is less than the showing that needs to be made for a warrant.

Eckenwiler: That's correct, your honor.

Sloviter: So the question is, can (d) be used for that purpose?

Eckenwiler: Yes, your honor. It can be used constitutionally for that purpose. And the reason I understand your honor's concern about those future cases, those hypotheticals. But I think it is clear from the Supreme Court's caselaw that Fourth Amendment issues must be measured on the basis of the facts before the court.

Sloviter: The question is, really, what can the government get? [Refers to a log of cell phone tracking.] They can get, here's 4:33 on the same day, 4:39 pm on the same day, 4:40 on the same day. That's pretty close.

Eckenwiler: And your honor, the calling records, the numbers that are being called, from whom calls are being received by the same user, we can compel them with a subpoena.

Sloviter: That's right. And as I read this, you can compel a lot of information that it looks like you wanted with a warrant. I don't understand -- I've been on this court for 30 years, more than 30 years. The magistrate judges that I have seen are not very grudging about granting warrants. If you could have gotten a probable cause warrant, why do you want to make the point that you don't have to show probable cause?

Eckenwiler: Well, it's interesting, your honor, because the rationale that was adopted in this case by the lower court wouldn't limit the reviewing court, the court to whom the application was presented to probable cause. Under the rationale that was articulated below, the court could demand proof by a preponderance of the evidence. Judge Lenihan's opinion said it's up to the court to decide, in effect, what showing could be made. It vests the trial court, the magistrate judge, with what's essentially unlimited discretion to decide what showing should be made. And the government submits, your honor, that that's an inappropriate exercise in judicial discretion.

Sloviter: You're concerned that the magistrates will give you the warrants even if they don't have enough basis? Is that really the government's concern? I mean, that's backwards.

Eckenwiler: Your honor, I'm saying the magistrate could demand an even showing higher than probable cause.

Sloviter: Then they'd go up on appeal and the district judge wouldn't accept that.

Eckenwiler: That's why we're here today. The magistrate demanded a higher showing than what's required under the statute.

Sloviter: But didn't require more than probable cause.

Eckenwiler: Your honor, that's true.

Sloviter: The five magistrates signed -- five! -- I've never seen that before. Did you ever see that before?

Eckenwiler: I have not, your honor.

Sloviter: Neither have I. Five magistrate judges signed on to this opinion affirmed by the district court. They didn't demand more than probable cause. They demanded just probable cause. A constitutional standard.