Identity theft has gone mainstream.Once a minor blip on the law enforcementradar screen, identity theft nowaffects more than 10 million Americans ayear, at an annual cost of more than $50billion. And the personal computer isbecoming the identity thief's tool ofchoice. The most recent ploy, known asphishing, involves e-mails that appear tocome from banks, online vendors, andeven federal government agencies. Designedto look like the real thing, these emailsask for personal information likepasswords, bank account numbers, andSocial Security numbers, which thethieves can then use to plunder bank andbrokerage accounts and apply for creditcards. Never give out personal informationover the Internet. If you receivean e-mail that appears to be from yourbank or brokerage, call customer serviceto double-check that it's legitimate.