Verizon, T-Mobile and others retain subscriber calls details and other data

Carriers are likely to find themselves in hot water, following the leak of a U.S. Department of Justice document showing the type of subscriber data collected by the major carriers and the length of time they're retained.

Apple was able to brush off similar consumer ire in April, blaming the iPhone's storage of a year's worth of location data (or local crowd-sourced Wi-Fi hotspot information, as Apple clarified) on a software bug. But the DOJ document, first reported by Gizmodo and created for law enforcement agencies that presumably request such data in support of cases, makes the intentionality of the practice quite clear.

Sprint, Nextel and Virgin Mobile retain subscriber information for an unlimited time, while T-Mobile ditches it after 5 years and Verizon, for post-paid customers, maintains it for 3 to 5 years. Data on cell towers used by the phone — which while arguably not "tracking" a user would show them, or at least their device, to be specific vicinity — is kept for a year by Verizon and 18-24 months by Sprint and Next. T-Mobile, states the document, retains the data "officially 4-6 months, really a year or more."

Verizon also holds on to text message details for a year, though the content of messages for just three to five days. None of the other major carriers keep records of text messages expect for Virgin Mobile, with keeps them for 90 days but requires a search warrant to hand them over.

Warrants are the exception, which prompted Sen. Patrick Leahy (D-Vt.) to propose legislation last year that would allow the release of email and other cloud-stored data only with a probable-cause warrant. A provision of the 1986 Electronic Communications Privacy Act, as Wired has reported, makes "reasonable grounds" reason enough.

The document additionally specifies information about pictures, bill copies, payment information, service applications, IP session information and retail stores' surveillance videos.

Verizon, looking to sidestep the April drama shrouding Apple, Google and others, wrote to U.S. Reps Joe Barton (R-Texas) and Edward Markey (D-Mass.) they would begin affixing stickers to new device screens that made customers take note of location settings (Unfiltered: Verizon Wireless labeling phones as tracking threats).

The sticker states, "To limit access to location information by others refer to the User Guide for Location settings and be cautious when downloading, accessing or using applications and services."

Apparently, Verizon doesn't lump itself among the "others."