Cellphones as Tracking Devices

Another federal court of appeals is grappling with the standards by which police powers of government may gather information about a person's location.

In Maynard, the DC Circuit overturned a criminal conviction obtained through use of evidence gathered from a GPS device surreptitiously placed on a suspect's car. The court said that the government needs a warrant issued by a judge following Fourth Amendment standards, before it can so use a GPS device to track a person.

In Pineda-Moreno, another GPS device case, the 9th Circuit reached an opposite conclusion and let a conviction stand.

The new case is from the 3rd Circuit. It doesn't involve a GPS device but instead has to do with cell site location information ("CSLI"), records that a carrier keeps about what towers handle what cellphone calls and when, from which a cellphone user's historical movements may be inferred.

The court in this case is also dealing with a very specific statute written to deal with government access to carrier records. 

But the court ponders issues similar to those considered (albeit on the way to opposite conclusions) in the GPS cases: is there an expectation of privacy in one's movements? Is a line being crossed where the government might be looking inside a particularly protected zone of privacy, such as a person's home?

The 3rd Circuit ends up overturning a magistrate judge's decision that the government needed to show probable cause to obtain the order for the CSLI records it was seeking. The court concludes that the magistrate judge imposed a higher standard on the government than both the words of the statute and the legislative history show that Congress had intended. Ostensibly because of the statute, but also I think reflecting the court's temperament and its readings of the same Supreme Court cases the other circuits are construing, the 3rd Circuit finds an intermediate standard - something between what the permissive 9th Circuit allowed and what the much stricter DC Circuit required - to be in order.

It's a muddle, in that the 3rd Circuit says that the magistrate judge nevertheless retains reasonable discretion to deny the government what it seeks, even if the correctly applied standard is met. The case is not over; the court has sent it back to the magistrate judge for further proceedings. Presumably, she can arrive at the same result she reached before, as long as she applies the correct statutory standard and gives appropriate reasons for whatever discretion she uses.

There's some interesting, inconclusive discussion in the case about whether the fact that a person knows that a phone company is going to keep records means that there can be no expectation of privacy in such information. I'll bet this kind of dialogue will take place in the arena of voluntary location-based services.

Right now, there's a lot of focus on privacy policies and what social media platforms and apps do to secure access and information from other users and the general public. But the government is going to have different standards. I'd expect that it will prove relatively easier for the government to obtain check-in information for a user of Foursquare, say, than to obtain the same person's CSLI or GPS data from carrier records.