Welcome to the 21st century, where we all carry tracking devices in our pockets and where one morning you might find an FBI-installed GPS tracking device on your car. In this age of location-based-everything, the legal question of whether or not the government has to get a search warrant based on probable cause before secretly tracking you becomes all the more important. Three recent court developments from across the country — and a Congressional hearing — put a fine point on this key privacy controversy for the mobile era.

In Philadelphia, at the Third Circuit Court of Appeals...

EFF yesterday filed the latest brief in its ongoing battle in the Third Circuit to protect the privacy of cell phone company records that reveal your past locations. There, the government appealed a lower court judge's denial of a government request for a court order to obtain cell phone location records without probable cause. In September, we won a great victory when the the three-judge panel reviewing the case agreed with EFF's arguments and held that federal law gives magistrates the discretion to require warrants for such data. The panel did not reach the question of whether the Fourth Amendment requires warrants in such cases — we think it does — but instead ordered the case back to the magistrate for her to develop a fuller factual record supporting the use of her discretion. However, the government threw a wrench in that plan, filing earlier this month a petition asking all of the judges in the Circuit — in legal terms, the entire court sitting "en banc" — to review and overturn the panel ruling. Yesterday's brief was our response to that government petition, arguing that the panel got the law right and that the case does not warrant reconsideration.

In Washington DC, at the DC Circuit Court of Appeals...

As the judges of the Third Circuit consider the government's petition in the cell records case, we hope they'll follow the lead of the D.C. Circuit Court which just two weeks ago denied a similar petition in U.S. v. Maynard, another location privacy case where EFF served as a friend of the court. In that case, agreeing with arguments made in EFF's brief, the appellate panel ruled that the warrantless installation and use of a GPS tracking device to monitor a suspect's car violated the Fourth Amendment's ban on unreasonable searches and seizures.

In Houston, at the Southern District of Texas Federal Court...

Making good use of both the Third Circuit's cell records decision and the D.C. Circuit's decision in Maynard, Magistrate Judge Stephen Smith of the Southern District of Texas issued an opinion on October 29th denying another government request to obtain cell phone location records without a warrant, much like the magistrate in Pennsylvania. Judge Smith has been issuing opinions requiring warrants for cell phone tracking for half a decade, but this may be his most well-reasoned and comprehensive opinion yet. Mindful of the Third Circuit's warning that judges should build a full factual record before requiring a warrant, Judge Smith assembled an incredible amount of information to support his conclusion that cell phone location records are accurate enough to invade your reasonable expectation of privacy under the Fourth Amendment. For concerned citizens and location privacy buffs, this opinion is a must-read.

On Capitol Hill...

A great deal of the information supporting Judge Smith's cell records decision came from a hearing in Congress this past summer where he himself testified. That hearing, on ECPA Reform and the Revolution in Location Based Technologies and Services, was in part held in response to legislative proposals made by EFF and others as a part of the Digital Due Process coalition seeking to clarify and strengthen federal electronic communications privacy law. Specifically, the DDP coalition proposes clarifying and strengthening the law to plainly require search warrants before the government can access your location records or track your cell phone in real-time, as described in testimony from DDP coalition member Marc Zwillinger of the tech law firm Zwillinger Genetski LLP. Smith especially relied in his cell records decision on the powerful testimony of information scientist Professor Matt Blaze of the University of Pennsylvania, which made clear how accurate cell phone location records and the cell carriers' tracking capabilities can be and just how much more accurate we can expect them to get.

We hope and expect that electronic privacy reform bills based on the DDP coalition's proposals will be introduced next year, so stay tuned to Deep Links for updates on that and on any new court developments in this fast-moving area of location privacy.