Most home page owners would never post their Social Security number on their sites. But many people post personal information, such as a family tree, that contains details almost as valuable to an identity thief as a Social Security number.

Information common to family trees, such as full names, birthdays, and cities of birth are all that a thief needs to obtain a copy of your birth certificate and, with that, a driver's license bearing your name and the thief's photograph. With those documents, s/he can open bank and credit accounts, rent an apartment, even get a job or a criminal record-all in your name.

A family tree also reveals your mother's maiden name, which is frequently used as the security password for bank and credit accounts.

Safeguarding your private information is the best measure you can take to prevent identity theft and credit fraud. Be selective about what you or your family members post on personal home pages--remember that if it's on the Web, it's available to the world.

• Never post your Social Security number.
• Avoid posting sensitive information about you or your family that could lead to impersonation.
• Make sure your relatives know about and agree to any information you do put on the Web.
• If you do post a family tree, make sure you and your family all use passwords other than your mother's maiden name for bank and credit accounts.