Text messages – and any sensitive information they contain – may last a lot longer than people realize.

Verizon Wireless stores the content of text messages for a year, according to a Justice Department document that was recently received via Freedom of Information Act request by the American Civil Liberties Union of North Carolina.

The other carriers do not store text message content, but they keep other text details around for up to seven years, Wired.com's "Threat Level" blog reported Wednesday in a story based on the document.

Text messages can contain sensitive banking information, especially since some banks send one-time-use security codes to customers as text messages. Customers might also send sensitive information, such as account numbers or passwords, to one another.

The document was written in 2010 as a guide for law enforcement agencies seeking information from carriers, the article said. Kevin Bankston, a staff attorney for the Electronic Frontier Foundation, told Wired.com that "I don't think there is anything on this list the government would concede requires a warrant."