Depending on the circumstances, police would generally need to meet one of three tiers of standards to get a court order to access to GPS data from a phone company, Orin Kerr, a professor at George Washington University Law School, tells TPMmuckraker: a certification to the court that the location information is relevant to an investigation (a court must grant this request); showing the court with "specific and articulable facts" -- say, that a suspect is involved in drug smuggling -- that the data is relevant; or, finally, showing good old probable cause to obtain a search warrant.
"Under a legal standard like this one, people who will never do anything wrong -- who have simply caught the interest of law enforcement -- will have their GPS info pulled," says Chris Calabrese, legislative counsel at the ACLU. Adds Calabrese: "GPS data should clearly be protected by the Fourth Amendment warrant standard, but right now it's not."
The GPS privacy issue blew up last week when a graduate student revealed that Sprint had given police customer location data 8 million times through a new online system set up by the company. Sprint says that represents "thousands" of individual customers, but has not revealed the exact number. Other wireless carriers are said to have their own systems in place.
Sprint says it follows the law and grants police officers access to specific customer location data only if they have a proper court order. Much of the relevant law is rooted in the 1986 Electronic Privacy Communications Act. So what determines how easy it for a given police offer to get an order?
There are a number of variables that determine which of the three standards police would have to meet, according to Kerr. They include where the request is made, whether it's by state or federal authorities, whether the police are seeking historical or real-time location data, and even, perhaps, what specific technology is used to pinpoint a cell phone user's location.
(It's worth noting that "GPS" is often used as a catchall term for a few techniques used, with varying effectiveness, to locate a phone. They include triangulation using cell towers and GPS, which involves satellites, according to forensic technologist Jeff Fischbach.)
One might think that the ambiguity on these points would make GPS data a ripe target for criminal defense attorneys. The ACLU's Calabrese says that's not so. "It has come up in surprisingly few cases," he says, noting location data is rarely challenged in court.
While the issue is gaining in prominence and is "ripe for reform," Calabrese says he knows of no bills in Congress that would address police surveillance using GPS.
On the constitutional front, the U.S. Court of Appeals for the D.C. Circuit heard arguments last month about whether police needed a warrant to put a GPS tracking device on the car of a suspected drug dealer. It turns out the key precedent is a 1983 Supreme Court opinion that a person traveling in public has "no reasonable expectation of privacy."
But in an aside in that case, U.S. v. Knotts, then-Justice William Rehnquist left the door open to further consideration of the issue, if 24-hour surveillance became widespread:
Respondent does not actually quarrel with this analysis, though he expresses the generalized view that the result of the holding sought by the government would be that "twenty-four hour surveillance of any citizen of this country will be possible, without judicial knowledge or supervision." ... if such dragnet type law enforcement practices as respondent envisions should eventually occur, there will be time enough then to determine whether different constitutional principles may be applicable.