Cellphones are the spies in our pockets, gathering information about whom we befriend, what we say, where we go, and what we read. That’s why Sen. Edward Markey, D-Mass., recently asked the nation’s major cellphone companies to disclose how frequently they receive requests from law enforcement for customer call records—including the content of communications, numbers dialed, websites visited, and location data. Sometimes police have a warrant, sometimes they don’t.

Seven companies provided information in response to the inqury. The letters Markey received, which were covered today in the Boston Globe, Washington Post, and New York Times, show that the quantity of requests for these records is staggering. T-Mobile and AT&T together received nearly 600,000 requests for customer information in 2012. AT&T has to employ more than 100 full-time workers to process them. And police demand for our call records is growing rapidly, with requests to Verizon doubling in the last five years.

This piece was originally published on Slate. Click here to read the full article.