The Indiana Attorney General’s office has information about security freezes, which are free for residents of Indiana (and some other states—you’ll have to check your own state’s laws if you don’t live here).
You can download the information here, or visit the Indiana Consumer website. I’ll put a link on the Fraud Prevention Resources page as well.
A security freeze (or credit freeze) prevents new lines of credit from being opened in your name, even if an identity thief has your Social Security number and other information, by adding an extra step to the credit application process.