ACLU urges wireless carriers to stop tracking customers' location

The American Civil Liberties Union is urging the major wireless carriers to stop storing data about their customers' location.

The four national wireless carriers -- Verizon, AT&T, Sprint and T-Mobile -- all keep records of which cellphone towers a phone uses for at least a year, according to a document released by the ACLU in September. This information could be used to determine a person's location. "But just because your network has access to these sensitive details does not mean that you should be collecting and storing this information," the ACLU wrote in a letter to the heads of the major wireless companies. The document on cellphone data, which the ACLU obtained through a Freedom of Information Act request from the Justice Department, also showed that the carriers retain data on phone calls and text messages. The Justice Department compiled the document to help police officers obtain evidence. "Customers are already paying money for their mobile service; they should not be paying with their personal information too," the ACLU wrote.