Reports of identity theft have grown rapidly over the past several years, and the resulting credit card fraud has surpassed $1 billion annually, congressional investigators said Thursday.

Complaints to consumer hot lines, the Federal Trade Commission and other sources show that Americans more than ever are at risk of having their money stolen and credit records wrecked.

"It seems we all know someone who's had his identity stolen," said Sen. Charles Grassley, R-Iowa. "This crime is getting more common all the time."

The General Accounting Office, Congress's investigative arm, said it is difficult to find out exactly how many people have fallen victim.

"Some individuals do not even know that they have been victimized until months after the fact and some known victims may choose not to report to the police, credit bureaus, or established hot lines," the report says.

From 1998 to the middle of last year, the Social Security Administration reported a fivefold increase in allegations of Social Security number fraud.

Credit card companies Visa and Mastercard reported that fraud losses rose from about $700 million in 1996 to $1 billion in 2000. Federal and private hot lines reported a steep increase in complaints.

"Each of these various sources or measures seems to indicate that the prevalence of identity theft is growing," the report said.

Using a Social Security number and easy-to-obtain personal information such as a name and address, it is fairly simple for a criminal to open a loan or credit card account in another person's name.

Identity theft is an old crime that has become much more common with the advent of the Internet.

Companies hold huge databases of personal information, and there are few laws that restrict the sale of that information from company to company. In Internet chat rooms, credit and calling card numbers are traded like currency.

Sen. Dianne Feinstein, D-Calif., wants to require prior consent before a company sells a person's information. Her bill would make it a crime to sell or display Social Security numbers to the public.

"Due partly to the growth of the Internet and other communications technologies, there is general consensus that the opportunities for identity theft are not likely to decline," the investigators wrote.