<snip>
The eye-openers:
■All of the mobile phone companies keep details about the location of cell towers used by every phone, for a year or longer.
■All of the mobile phone companies keep records about voice calls and text messages received and sent for a year or longer. Verizon stores the contents of every text message for three to five days. (The others don't keep the text.)
■IP session information -- tying your phone to an IP address -- is kept for a year by Verizon and 60 days on Sprint and Nextel.
■IP destination information -- which IP addresses you connected to -- is stored for 90 days at Verizon and 60 days on Sprint and Nextel.
<snip>
http://www.infoworld.com/t/internet-privacy/mobile-phone-companies-keep-your-records-longer-you-think-175466