Requests for cell phone data have increased significantly over the last five years as police rely more on the evidence these phones provide.
A cell phone is more than just a handy way to make calls. The data it stores has personal information about who you call. Because calls go through the nearest cell tower, it provides accurate location tracking as well.
Given the amount of information stored by cell carriers it's no surprise that all levels of law enforcement are making more requests for cellphone data.
What is shocking is the number of requests that were made last year.
During 2011, cell phone carriers responded to 1.3 million requests by law enforcement for cellphone data, according to The New York Times.
The number of actual individuals affected could be much larger since requests can look for information from multiple subscribers.
Cell phone carriers provided the information in response to a public accounting by Rep. Edward Markey, a Massachusetts Democrat.
Federal law on location data requests is unclear so it's difficult for carriers to know how to respond. Carriers often require a subpoena, warrant, or court order when turning over subscriber information.
In the case of emergencies there may not be time to follow formal requirements. Then carriers have to make a judgment call on the request's legitimacy. Without a clear legal definition of what "emergency", carriers can't tell what is actually meant by an "emergency" request. Does it mean a kidnapping or a tight interoffice deadline?
The Supreme Court has weighed in on the issue of location tracking, requiring law enforcement to get a warrant before using a GPS tracker on a man's car. But that doesn't give clear guidance about how the law should deal with cellphone data which can carry a lot of personal information.
With the number of requests each year, there is a good chance that innocent subscribers are being affected. Clarification of the law could improve consumer protection while still allowing police to use the data in criminal cases.
Markey launched his investigation after The New York Times published an article in April indicating that police were making more cell phone data requests.