Two congressmen are trying to pry information out of wireless carriers about how closely they track their customers' whereabouts.
Letters sent to AT&T, Sprint, Verizon, and T-Mobile this week ask what personally identifiable information is stored, how long it is kept, and for what other purposes it's used.
Reps. Ed Markey (D-Mass.) and Joe Barton (R-Texas) asked for responses no later than April 19. Their request came after Germany's Zeit Online published data showing that a cellular provider kept track of tens of thousands of locations that one person visited over six months.
Their letters could prove more important than they might seem: this type of data collection is prized by police, but details about each company's procedures are hard to locate, and in many cases impossible.
If the responses from the companies are illuminating, they could influence the forthcoming debate in the U.S. Congress about whether to require police to obtain search warrants before tracking someone's location.
Sen. Ron Wyden (D-Ore.) is drafting legislation requiring judicial approval and a showing of probable cause to learn the locations of cell phones and, via GPS tracking, cars. (See CNET's Q&A with Wyden and article about his draft bill.)
Even though police are tapping into the locations of mobile phones thousands of times a year, the legal ground rules remain hazy, and courts have been divided on the constitutionality and legality of the controversial practice. In September, the first federal appeals court to rule on the legality indicated that no search warrant was needed, but sent the case back to a district judge for further proceedings.
Because the two-way radios in mobile phones are constantly in contact with cellular towers, service providers know--and can provide to police if required--at least the rough location of each device that connects to their mobile wireless network. If the phone is talking to multiple towers, triangulation yields a rough location fix. And, of course, the location of GPS-enabled phones can be determined with near-pinpoint accuracy.
CNET was the first to disclose the existence of police asking for warrantless tracking of cell phones in a 2005 news article.
The Obama Justice Department has argued that warrantless tracking is permitted because Americans enjoy no "reasonable expectation of privacy" in their--or at least their cell phones'--whereabouts. Justice Department lawyers have argued in court documents that "a customer's Fourth Amendment rights are not violated when the phone company reveals to the government its own records" that show where a mobile device placed and received calls.