Schneier on Security

Text Message Retention Policies

The FBI wants cell phone carriers to store SMS messages for a long time, enabling them to conduct surveillance backwards in time. Nothing new there — data retention laws are being debated in many countries around the world — but this was something I did not know:

Wireless providers’ current SMS retention policies vary. An internal Justice Department document (PDF) that the ACLU obtained through the Freedom of Information Act shows that, as of 2010, AT&T, T-Mobile, and Sprint did not store the contents of text messages. Verizon did for up to five days, a change from its earlier no-logs-at-all position, and Virgin Mobile kept them for 90 days. The carriers generally kept metadata such as the phone numbers associated with the text for 90 days to 18 months; AT&T was an outlier, keeping it for as long as seven years.

An e-mail message from a detective in the Baltimore County Police Department, leaked by Antisec and reproduced in a 2011 Wired article, says that Verizon keeps “text message content on their servers for 3-5 days.” And: “Sprint stores their text message content going back 12 days and Nextel content for 7 days. AT&T/Cingular do not preserve content at all. Us Cellular: 3-5 days Boost Mobile LLC: 7 days”

That second set of data is from 2009.

Leaks seems to be the primary way we learn how our privacy is being violated these days — we need more of them.

EDITED TO ADD (4/12): Discussion of Canadian policy.

Posted on March 21, 2013 at 1:17 PM • View Comments