Another cellphone location tracking case: this time the government need not meet 4th Amendment probable cause requirement

The original appearance of this entry was in Danny Weitzner - Open Internet Policy

I learned from an Ars Technica item of yet another federal court ruling on cellphone location tracking (US District Court for the Southern District, Gorenstein, Mag., Opinion and Order 05 Mag. 1763, 21 December 2005). This time, the magistrate found that the government could gain access to at least a particular type of location information (cell site information) without satisfying the full 4th Amendment probable cause requirement.

The result in this new opinion by the 4th federal magistrate writing in as many months takes the opposite view from the first 3. He concludes that the location information (at least cell tower information) is available to the government without satisfying the 4th Amendment probably cause standard. All they need to do is to show “specific and articulable facts” that the information sought is relevant to an ongoing criminal investigation. This is less than the full 4th Amendment standard, but entails significant independent judicial oversight of the privacy intrustion, unlike the virtually non-existent oversight required to get ‘dialed number’ information. (See my earlier post on this subject for more details.) Magistrate Gorenstein comes to this conclusion through what I believe may be a mistaken reading of the relevant statute. The reasoning is so convoluted that I hesitate to even try to summarize it here. In short, he concluded that a statute passed in 1994, the Communications Assistance for Law Enforcement Act (Pub. L. 103–414, 47 USC 1001, et. seq), implied, though did not explicitly state, that the lower standard was applicable to cell site location data. I don’t believe that this is what the statute actually says, and the the Congressional Committee that wrote the statute didn’t either. The committee report (aka legislative history) explains that CALEA:

Expressly provides that the authority for pen registers and trap and trace devices cannot be used to obtain tracking or location information, other than that which can be determined from the phone number. H. Rep. No. 103-827.

Judges sometimes do have good arguments for interpreting statutes as they see them, even if the intepretation contradicts the ‘legislative history’. After all, the Congress writes the statute so they’re expect to get it right so that we can all understand it on its ‘face’, without having to resort to extra explanations.

All that said, there’s reason to be other than completely gloomy about this result from a privacy perspective. First, this magistrate specifically limited his ruling to situations in which the government only seeks information about the cell site with which the target cell phone is actually communicating. That reveals someone’s location with a 10 mile to 2000 ft radius (depending on the density of cells) but does not enable the goverment to instantaneously ‘triangulate’ a person’s location to a finer resolution. (It is possible to infer a rough map of were the person travels, however.) And second, it’s generally the case that when lots of trial courts start coming to opposite conclusions on the same or related questions, there’s greater pressure of appeals courts (who have broader jurisdiction) to resolve the differences and settle on one common interpretation of the law. That’s more likely to happen on this issue now that there is disagreement. (There are some legal technicalities that make an quick appeal difficult, but it’s likely to happen sooner or later.)

A report on the first stage of this case is on Declan McCullagh’s Policy Blotter (2 September 2005).