Further expose yourself digitally by sharing a wireless connection with the entire neighborhood. Without digital encryption you can share the contents of your hard drive with anyone on the street.

For maximum risk, commit the computing equivalent of licking a handrail in a New York City subway station and do some online banking on a public computer -- like the one at the library or a public cafe. Bonus points are added if your Social Security number is your user ID for any transactions.

A keyword logger or tracking device installed by a ne'er-do-well can capture any information you type, such as your user name and password, and cause havoc in your financial life

In fact, the easiest way to become a victim is just to let your guard down completely and trust in the basic good nature of humanity. If someone empties your account -- well, maybe they needed the money more than you did!

Safe surfing is really the only way to protect yourself -- using common sense more than jumping through technological hoops -- which basically entails being careful about what information you divulge and how.

Because the presence of an infiltrator often remains undetected, current measures of identity theft and fraud aren't completely accurate. Some people have no clue how they were victimized, so the proportion of crimes that occur due to key loggers and viruses just isn't known.

"It's the type of attack that would be pretty hard to detect, and the way that we measure attacks is usually by asking people, 'Have you been a victim of this kind of attack?' It doesn't show up very often," says Fred H. Cate, University of Indiana law professor and director of the Center for Applied Cybersecurity Research.

The impact of threats lurking online is more apparent from the view at the frontlines of information technology.

Jon Ramsey, chief technology officer of SecureWorks, an information security company, says protecting corporations from hackers means thinking like one to identify any holes in security.

"We've seen posts from hackers on blogs that they have so much information it will take them years to go through it all," he says.

Ramsey says someone's full identity sells for $100 to $200, which would include their name, e-mail address, Social Security number, credit card numbers with the card security code and the credit limit.

"Unfortunately they've been so successful at getting bank account numbers and socials -- that stuff goes for $10," he says.