Identity theft is generally a pretty low-tech crime. The bad guys steal your mail or pilfer your trash, coming up with enough personal information to apply for bank accounts, credit cards and loans with your name and credit rating but with their address. They can even appropriate your existing accounts. All it takes is having your name, address, date of birth, and Social Security number. Before you know it the crooks have bought goods, bounced checks, and drained your bank accounts, leaving a world of heartbreak for the victims as they try to repair the damage.
The single greatest deterrent to identity theft is probably a paper shredder. Get one and use it for anything you throw away that contains personal information. Oh, and NEVER put outgoing mail in your mailbox for pickup by the carrier. Take it to the post office or to a local post office box. It is very difficult to measure the cost of identity theft. The U.S. General Accounting Office tried to do so in a 2002 report and finally concluded that it simply could not be done with any precision. Many identity thefts aren't even noticed, for one thing. What's that $30 charge on your credit card bill? Oh well. Even many identity thefts that are noticed aren't reported. And when they are reported it is often to different federal, state and local agencies that don't necessarily speak with each other.
News source: I, Cringely