Cell carrier data requests have surged in recent years, and thanks to a recent request from Senator Ed Markey (D-MA), we can now report exactly how much. In a statement to the Senator, T-Mobile and AT&T disclosed a full 600,000 data requests that were submitted to federal and local law enforcement in 2012, often containing the customers' contact lists and hundreds of daily location points. Combined with Sprint, which previously reported more than 1,500 requests per day, that's well over a million. Verizon declined to give out specific numbers, but said the company's volume of requests had doubled in the past five years.

It's particularly troubling because courts see the data as a "business record" belonging to the carrier, so law enforcement doesn't need a warrant to see it. At the same time, the records are hugely revealing in an era of mobile computing. "Our mobile devices quite literally store our most intimate thoughts as well as the details of our personal lives," said ACLU counsel Christopher Calabrese. "The idea that police can obtain such a rich treasure trove of data about any one of us without appropriate judicial oversight should send shivers down our spines."