DENVER -- Imagine receiving a phone call from a stranger who knew your most private thoughts, knew what you looked like, knew your Social Security number, and even knew how much you make and where you work. That happened to a Colorado woman after she took her computer to a major electronics store. Her situation may be surprising given all the warnings about identity theft. But it's not surprising if you think for a moment about what's on your personal computer. There may be files about your income, business records, taxes, personal e-mails, dirty jokes, pictures and more. It's all...