People often ask me what the best way is to prevent identity theft. Besides the obvious (e.g. not having "passwords" as your password), the best way you to protect yourself after your information is stolen is placing a "freeze" on your credit. A freeze is a procedure where the credit bureau will refuse to issue a report about you to a prospective creditor who is attempting to issue credit in your name. The effect of the refusal is that the creditor won't open the account.
Any person can ask to have their credit frozen. If you're a Minnesota resident, all you have to do is send a letter requesting your file be frozen to one of the Big 3 credit bureaus (Equifax, Experian, and TransUnion). Include a copy of your drivers license along with a $5.00 fee. If you have already been a victim of identity theft, include a copy of a police report in lieu of the $5.00.
It probably goes without saying, but even you yourself will be prevented from opening a credit account in your name while the freeze is in place. Consequently, if you're contemplating buying a car or taking out a mortgage, you'll need to contact the credit bureaus in the same way to "thaw" your credit.