C/Net reports that a memo entitled “Retention Periods of Major Cellular Service Providers“, obtained from the Department of Justice by the ACLU through the Freedom of Information Act, shows the data retention policies of six major U.S. mobile carriers.
Dated August 2010, the memo says it’s directed for “Law Enforcement Use Only,” so it was written specifically for police and legal authorities in cases where they need to obtain cell phone records.
According to the ACLU, the chart begs the question, shouldn’t all cell phone companies reveal their data retention policies and under what circumstances they turn over information to law enforcement in their user agreements or on their websites?
Mobile carriers capture call detail records (who you called and when), text message details (who you texted and when), text message content, bill copies, payment history, and even which cell towers you use. Another category, called Subscriber Information, presumably tracks your name and all necessary contact details.
Carriers differ in which data they capture and for how long.
Verizon holds your call detail records and your text message details for 1 year, T-Mobile for 2 to 5 years, and AT&T for as long as 7 years. Verizon also keeps track of the cell towers you use for 1 year as does T-Mobile, while AT&T has been keeping that information since July 2008.