from the where-your-privacy-has-gone dept
The problem is a series of precedents that, as legal scholar Richard Posner has observed, enable the government to do a two-step end run around the Fourth Amendment. In the 1974 case California Bankers Association v. Schulz, the Supreme Court ruled that the Bank Secrecy Act, which required financial institutions to collect certain kinds of information from customers, did not run afoul of the Fourth Amendment's privacy protections. (Similarly, Enhanced 911 rules implemented in 1998 required telecom providers to make their networks capable of pinpointing the locations of cell users for the convenience of 911 operators.) The Court reasoned that "the mere maintenance by the bank of records without any requirement that they be disclosed to the Government" did not constitute an "illegal search and seizure." But two years later, in U.S. v. Miller, the Court determined that individuals lost their "expectation of privacy" in such information once it had been turned over to a third party, such as a bank. And businesses such as banks, unlike individuals, could not claim Fourth Amendment privacy interests in their records.
That brings us to 1979's Smith v. Maryland, in which the Court determined that no "search" was conducted, for Fourth Amendment purposes, when police sought to obtain from telephone companies a list of the numbers dialed from a particular telephone. The Court's reasoning was two pronged: In part, the justices relied upon the "third party" rationale of Miller. But they also noted the ways that such information gathering was distinct from, and less intrusive than, eavesdropping on the calls themselves: "Neither the purport of any communication between the caller and the recipient of the call, their identities, nor whether the call was even completed is disclosed by pen registers."
Different jurisdictions have differed on how this logic applies in the case of cell tracking, where there's the added hurdle of language in the Communications Assistance for Law Enforcement Act that would appear to forbid using a mobile phone as a GPS device without a full-fledged search warrant. It seems likely that, at least in the near term, judges will rely on such statutory constraints to check such tracking. But it also looks like a good reason for the courts to revisit this whole line of Fourth Amendment jurisprudence, and reconsider whether, when so much data about us is stored in a variety of "third party" databases, it makes sense to presume citizens have no reasonable expectation of privacy in such information, even when the "third party" has pledged not to share it.