With the privacy laws that are in effect now, your text messages and emails, along with every sight online you visit, and picture you upload to the Internet or send through text message can be saved for up to two years. Even if you clear your browser history or delete the messages, the government has the ability to access this information and possibly use it against you if they wish.
This is an issue with the 4th Amendment. The government doesn't have a warrant to access your information or store it for multiple months.