"Identity theft occurs when someone obtains your personal information without your knowledge to commit fraud or theft. How does that happen? A criminal can co-opt your name, obtain your Social Security or credit card number, or get their hands on some other piece of your personal information for their own use. Here are a few ways that identity thieves work: 

• They call your credit card issuer and, pretending to be you, change the mailing address on your credit card account. Then they run up charges on your account. Because the bills are being sent to the new address, you won't realize that there's a problem.

• They open new credit card accounts, using your name, date of birth, and Social Security number. When they use the credit card and don't pay the bills, the delinquent account is reported on your credit report.

• They establish cellular phone service in your name.

• They open checking accounts in your name and write bad checks with these accounts.

 Should you become a victim of identity theft, this is what you should do.

 1.     Contact the three credit reporting agencies:   Equifax  Experian  Transunion - You need to put a fraud alert on all three of your credit reports. This has three effects:

 A.    You get a free copy of your credit report,

 B.    The credit reporting agencies remove your name and address from the pre-approved offers list.

 C.    Any new credit grantor will be instructed to telephone you to verify that you really want to open the account. Experian has an automated fraud alert telephone number, but they will only put a temporary fraud alert on your report. In order to have a permanent fraud alert placed on your Experian report, you have to send them a letter with a photocopy of your driver's license and the first page of your telephone bill. The fraud departments of Equifax and Transunion do not take reports after business hours.

2.     When you receive your credit report, there is a telephone number, which you can call to dispute any items. You will be required to give them the confirmation number on the credit report that you received.

3.     Follow up all of your telephone calls with certified letters. This is the first and most important step you should take. Anyone trying to obtain credit in your name and using your social security number is going to have a credit check run on them. This will hopefully nip any further fraud in the bud. Having hard copies of all correspondence will help you contest past and future fraud claims.

If you have had mail stolen, put a hold on your mail at the post office. If the mail isn't in the mailbox, then it can't be stolen. You will have to go down and pick it up every day for a few weeks, but given that you are about to receive a whole bunch of new financial information in the mail, it's worth it.

4.         Call all of your credit card issuers and have them cancel and have them get you new cards with a new account number issued. 

5.         Call all companies with which you have banking, investment or retirement accounts.  Thieves are not beyond attempting to wire transfer funds out of your investment account, particularly if they have all of your account information out of your mail. The safest thing to do is to open new accounts and transfer all of the assets from your old accounts to your new accounts. If that can't be done, you should arrange to password protect your account from any changes. 

In addition, you will have to pay attention to any automatic payments that may be made from your old bank accounts. You will have to stop those and set up new ones from your new bank account. Pay particular attention to this, as your creditors will not be happy if their payments bounce!

 6.     Call all of your utilities and inform them of the fraud. If you can't get a new account number issued, try to have them password protect the account. This won't always be possible, but at least you will have informed them of the fraud.

 7.     You can also file a complaint with the FTC. The FTC serves as the federal clearinghouse for complaints by victims of identity theft. While the FTC does not resolve individual consumer problems, your complaint helps us investigate fraud, and can lead to law enforcement action. The FTC enters Internet, telemarketing, identity theft and other fraud-related complaints into Consumer Sentinel, a secure, on-line database available to hundreds of civil and criminal law enforcement agencies worldwide". 

Note: Thanks to the Motley Fool and the US Government Identity theft division for the above information on Identity Theft