Secret Memo Reveals Which Telecoms Store Data the Longest

Wired: If you’ve ever wondered what kind of data your wireless provider has about you, now you can find out. An internal Justice Department memo titled “Retention Periods of Major Cellular Service Providers,” has been obtained by the ACLU through a Freedom of Information Act request.

Surprisingly, the year-old document reveals that data retention practices vary quite a bit by provider. For example, while T-Mobile saves your cell tower history (which provides key information about your location) for four to six months, AT&T saves that information for more than three years. And while most carriers don’t store the content of your text messages for more than a day, Verizon saves those messages for three to five days.