Here’s a recent statistic from an American study:
"Sprint Nextel provided law enforcement agencies with its customers' (GPS) location information over 8 million times between September 2008 and October 2009. This massive disclosure of sensitive customer information was made possible due to the roll-out by Sprint of a new, special web portal for law enforcement officers."
More on the blog of a PhD candidate in informatics, Slight Paranoia.
We have had some debate in Canada about law enforcement’s right to collect from ISPs (without a warrant) the name and address of people behind IP addresses. Cases have gone both ways on that. Proposed federal legislation (Bill C-47) will if passed dispense with the putative need for a warrant and require ISPs to turn over this information on mere request. The Privacy Commissioner of Canada has said she has seen, and the government in her view has produced, no evidence that such a dramatic measure was necessary.
What about geolocation data by the operators of mobile phone services? There was a case a couple of years back where Rogers had provided the location from which a series of calls had been made, as part of a criminal investigation, though the provision of the information did not seem to have been challenged by anyone.
Is this OK? Should people be as concerned about this as about disclosure of the personal information behind IP addresses? (That is, some people are concerned and some people think it’s normal or desirable, including most law enforcement people…)
Does Bill C-47 apply to this information too?
Have I missed the debate about this?
If it’s any comfort, there doesn’t seem to be any legal authority in the US for providing this information either.
While I haven't looked closely enough at Bill C-47 to see whether this type of geo-location information is included, I can tell you that the use of cellular phone positional triangulation has become fairly common place in criminal law.
I personally have dealt with it in several cases where, after the fact, a tel-co's cell phone tower records are subpoenaed and then used at trial to purport to provide a location of the accused (or at least his / her cell phone) during the commission of an offence. My battles in this area have largely revolved around the expertise required to translate this information into something probative for a trier-of-fact. It is sadly common to see crowns attempt to tender a generic "security director" at a phone company as an expert on this subject, when in fact they haven't the foggiest clue how the data is generated or what it means. In my view, and several court decisions support this view, someone with an engineering background and knowledge of the science behind cellular telecommunications is necessary to give fair evidence on what facts can (or cannot) be obtained from this data.
The question that has not arisen as commonly relates to your query about GPS location. One might argue that the GPS system, which can provide a considerably more accurate location, should be subjected to more rigorous judicial scrutiny before it is handed over without warrant or other statutory authority to police. What is the privacy interest in one's public location? These questions are not as simple to answer.