THE SCAM: Trolling social networking sites
HOW IT WORKS: Thieves check out Facebook and Twitter looking for any piece of personal information they can use to search for your address, such as your name or phone number. "Once they know where you live, they can submit a change of address form and have your mail sent to their P.O. box," says John Sileo, founder of ThinkLikeaSpy.com, a Denver-based identity theft prevention company. Thieves can even figure out your passwords using the seemingly innocent information you post online, like your pet's or kids' names-terms many people often use as passwords. Once they have all that information, it's easy for them to siphon money from your bank account.

PROTECT YOURSELF: Don't overshare. "Never put your correct birth date or your hometown on your Facebook page," says Sileo. What ID thieves can do with those two tidbits is scary. In 2009, researchers at Carnegie Mellon University discovered a formula that can deduce a person's social security number using just her birth date and birth state. And once thieves have your social security number, they can do everything from access your credit cards to obtain a loan in your name.