identity theft.

We all walk around with a number. Social security numbers have been around since 1936 and these days it's the one national way you're identified.
If yours has been compromised call the three major credit reporting bureaus... Trans Union, Equifax, and Experian... And ask them to place a fraud alert on your account.
Follow that up in about a month or so by asking for a copy of your credit report. You're allowed one free report every year by each bureau. If you stagger your requests you can continually see if any new accounts have been opened in your name.
Also.... check your various accounts and statements carefully. If you notice any questionable activity notify that group and authorities right away.
Other things to watch out for: Missing bills which could signal someone has taken over your account and changed your billing address to cover his tracks... receiving credit cards you didn't apply for... being denied credit for no apparent reason... and getting calls from debt collectors or businesses about services or merchandise you never purchased.
You may not encounter any problems, but if you stay on top of your financial situation you'll be ready to take action.