Federal Court Puts Limits on Cellphone Tracking

Privacy advocates gain key victories in high-profile battle

The GOP debate Thursday set viewership records for an obvious reason: One never knows what Donald Trump, the loose-lipped real-estate mogul might say. But many analysts believe the most significant exchange was when New Jersey Gov. Chris Christie and Kentucky Sen. Rand Paul sparred over warrantless searches by the National Security Agency.

Christie argued for giving officials the "tools" to collect data. Paul shot back: "You get a warrant." The issue centers on the Fourth Amendment, which offers the public protection against "unreasonable searches and seizures." The matter goes far deeper than presidential politics, as such cases wind their way through the courts.

Neither candidate mentioned a relevant federal ruling late last month in the U.S. District Court covering Northern California. Officials sought the right to track suspects' Cell Site Location Information, or CSLI, for 60 days without gaining a warrant. Such location information lets law enforcement track the whereabouts of our cell phones in relation to cell towers.

According to the court, "(m)ost modern smart phones have applications that continually run in the background, sending and receiving data without a user having to interact with the cell phone." This gives investigators a vast amount of information about the people they are tracking.

In its amicus brief calling for the warrant requirement, the American Civil Liberties Union of Northern California quoted from a 2010 federal ruling: "A person who knows all of another's travels can deduce whether he is a weekly churchgoer, a heavy drinker, a regular at the gym, an unfaithful husband, an outpatient receiving medical treatment, an associate of particular individuals or political groups".

Unfortunately, case law over this particular issue of cell phone tracking has been less than clear. Government officials note the wireless companies include disclaimers stating that they might turn over such data to the government, which they believe to be sufficient warning to the public.

The U.S. Supreme Court has dealt with cell phones and privacy, but the CSLI tracking information is a newer matter. Nevertheless, Judge Lucy Koh recounted various federal rulings and found some basic principles apply: Notably, "the expectation of privacy is at its pinnacle when government surveillance intrudes on the home"; long-term surveillance efforts undermine privacy; and cell phones aren't just phones — they "can reveal a wealth of private information about an individual."

The government argued the public can avoid their surveillance by not using a cell phone. But Koh rejected that argument: "Considering the ubiquity of cell phones, and the important role they play in today's world, it is untenable to force individuals to disconnect from society just so they can avoid having their movements subsequently tracked by the government."

She ruled that the government needs a warrant — and not just a court approval, which is based on lower standards of proof. Warrants require probable cause.

In a previous California high-court case, the state's justices had ruled that a cell phone was not fundamentally different from a cigarette pack in granting police officers unlimited power to search them. That was overturned by the U.S. Supreme Court in a 9-0 decision. Obviously, there's a huge difference between searching a cigarette pack for hidden drugs and tapping into all of a person's contacts and databases in a modern cell phone.

Fortunately, as technology advances so too are courts' — and legislatures' — understanding of these matters. "Statutory laws need to be updated for the modern world," said ACLU attorney Nicole Ozer, because "law enforcement is taking advantage of these outdated laws to get information."

When the Legislature returns from session, it will revisit the California Electronic Communications Privacy Act (SB 178), which is moving forward on a bipartisan basis. It sets consistent standards for the government's access of all electronic communications. It specifically addresses the CSLI matter, and would require police agencies to obtain a warrant before tracking Californians' whereabouts via their cell phones.

So clearly the courts and laws are continuing to address the issue, with Koh's ruling the latest example that the Paul position might be winning the day.