Hijacking of personal information for fraud or theft made up 42 percent of the 204,000 fraud complaints filed with the Federal Trade Commission (FTC) last year.
Identity-theft complaints grew from 23 percent of the FTC's Consumer Sentinel database in 2000 when the problem also topped the list of consumer fraud headaches.
Armed with that information, they can then apply for credit cards or bank loans, set up cell phone service or pass bad checks under someone else's name.
Last week, a Seattle man was sentenced to more than two years in federal prison for stealing identity information from the garbage cans and mailboxes of almost 400 victims.
A day later, police in Washington state said they cracked an identity theft ring, seizing a huge amount of stolen mail, paperwork bearing Social Security numbers, forged receipts, equipment for making fake driver's licenses, and maps of mail routes.
Recent victims include Oprah Winfrey and Tiger Woods.
Complaints about identity theft in 2001 outpaced Internet auctions, which accounted for 10 percent of consumer gripes; Internet services, at 7 percent; and shop-at-home and catalog offers, which made up 6 percent of the database.
The FTC statistics coincide with what experts say is increasing awareness and increasing incidence of identity theft as the Internet makes personal information more readily accessible.
Privcy advocates have said the number of people victimized by identity theft may be as high as 750,000 a year.
Most victims of identity theft eventually recoup their lost money, but they also suffer damage to their credit records and invasion of privacy.
The FTC's identity theft hot line gets about 1,700 calls weekly.
In November, the Supreme Court ruled that victims of identity theft or other credit fraud cannot stretch a two-year deadline to sue companies that collect or spread bad information, even if the victims don't learn of the problem until it is too late.
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