These are fascinating questions which are still legally unresolved: is it legal to geolocationally track a person or is it an unconstitutional search? And if so, do you need a warrant? More precisely, is there a constitutional protection for geolocational privacy?
As I am not a lawyer I will pass you on to this lengthy blog post at SCOTUSblog. It discusses what is at the moment the key ruling by the Supreme Court on geolocational tracking, US v. Jones (2012).
In Jones the Supreme Court ruled in favor of the defendant, who had had a tracking device placed on his car by the police. The Court held that this was a search under the Fourth Amendment. Many privacy advocates at the time saw this as a victory for privacy rights. For a number of reasons however, the case did not substantially turn on geolocational privacy rights.
Subsequent to this case (it says here in Wikipedia) it has been found that you do indeed need a warrant for geolocational tracking:
“In October 2013, the Court of Appeals for the Third Circuit addressed the unanswered question of “whether warrantless use of GPS devices would be ‘reasonable — and thus lawful — under the Fourth Amendment [where] officers ha[ve] reasonable suspicion, and indeed probable cause’ to execute such searches.”United States v. Katzin was the first relevant appeals court ruling in the wake of Jones to address this topic. The appeals court in Katzinheld that a warrant was indeed required to deploy GPS tracking devices, and further, that none of the narrow exceptions to the Fourth Amendment’s warrant requirement (e.g. exigent circumstances, the “automobile exception”, etc.) were applicable.”
Here are questions I think are still unresolved:
1. If you have to get a warrant for GPS tracking, do you have to get one for other forms of geolocational tracking, such as cell site data? Or can these be obtained through other legal recourses? What about other non-physical (electronic) tracking?
2. Does the warrant have to provide probable cause of an individual, or can you get bulk warrants (as revealed in the case of the FISA Court) based on other grounds? Or on “reasonable suspicion”?
3. If you briefly track someone rather than for an extended period of time (as was the case in Jones) is this constitutional (Justice Sotomayor argued it was not)? What if you were tracked briefly by a number of different methods (cell phone tracking, apps leaking locational info, emails, etc) at what point would these add up to extended tracking? I’m thinking Big Data here obviously.
4. Could locational information be considered voluntarily shared metadata? And would that make it less protected? So in the same way you are deemed to have shared your cell phone call (meta)data with a third party (the telco), have you shared your locational data? (I’ve been wondering about this since I saw the FISA Court order last June.)
5. Does technology itself reduce expectations of privacy (which may allow or justify increased government surveillance)? Alito: “New technology may provide increased convenience or security at the expense of privacy, and many people may find the tradeoff worthwhile. And even if the public does not welcome the dimunition of privacy that new technology entails, they may eventually reconcile themselves to this development as inevitable.”
6. Conversely, as mentioned in Q.3, Sotomayor argues that awareness of being watched has a chilling effect: “Awareness that the Government may be watching chills associational and expressive freedoms. And the Government’s unrestrained power to assemble data that reveal private aspects of identity is susceptible to abuse.” In everyday practice, who is correct–Alito or Sotomayor? Another way to ask this is to ask if Orwell or Greenwald is correct. In 1984 Orwell suggests that (at least to some extent) you get used to Big Brother watching you all the time and adapt. Greenwald, in his latest book, argued that it had a chilling effect. (Katy Crawford has gone further and argued that it produces “anxiety.”) I guess no matter what you feel about it; what are the effects of knowing/suspecting you’re under constant surveillance?
6. What is the legal situation in other countries?
Edited to add: 11th Circuit confirms need a warrant for cell tower tracking (US v. Davis).