Q. Someone has stolen my financial identity. What shall I do?

A. I have not had much experience in this area, so this column is a composite from several secondary sources.

It has been estimated that more than 500,000 Americans suffer this fate each year, with seniors especially vulnerable. The best defense is a good offense. We have all been warned about protecting credit card information. But your social security number is even more important.

Never give out your social security number unless there is a legitimate reason to do so. Unfortunately many who really do not need to know will demand such information, and there will be times when bullying tactics are used to get the number. Once it is in the wrong hands, or the wrong employee's hands, then it may be years before the damage can be stopped.

The social security number can be used to obtain other information such as a name or address. Then applications can be made for bank loans, credit cards, accounts, etc.

Once victimized, a person should vigorously start a defense. No one will step forward and help you. A police report should be filed each time a "theft" occurs and Social Security should be notified. I would suggest that the three credit card reporting agencies be contacted, both to alert their fraud divisions and to put a written warning on record: Trans Union (800)680-7289; Experian (888)397-3742; and Equifax (800)685-6285. Each credit card company needs to be notified and have them place a fraud alert for each card. Also, review your credit report from each company each year, taking advantage of your right to a free report.

A recent United States Supreme Court case held that if information has been on a credit report for more than two years, the credit reporting agency is not liable to the victim, even if the information was wrong and damaging, and even if the victim had no reason to know it was even there.

Finally, be prepared to be frustrated. The police, store clerks charging on accounts attributable to you, banks, and even public institutions such as Social Security and the Federal Trade Commission may be disinterested, or downright unresponsive, to your pleas for help. So once it happens, it is up to you.

Thus, guard your social security number just as you guard your credit card information.