"Every one of you . . . is a commodity," Internet security expert Linda Criddle said at the Utah Attorney General's Economic Crime Conference at Salt Lake City's Embassy Suites. "Somebody is willing to pay to know the color of your eyes."
That kind of personal information can give criminals access to financial accounts, help them select and profile potential victims, and even put users' friends and relatives at risk, Criddle said.
Criddle described a family tree her own father posted online to display the fruits of his genealogical research. He took it down once she pointed out that "mother's maiden name" is a common security backup question for online accounts.
"Utah is a big state for genealogy," she said. "If you are into genealogy, you should not be putting that information out there."
Online obituaries, wedding registries and birth announcements often contain much of the same data - along with a notice to potential identity thieves that those named are involved in an emotional event and may not notice new, mysterious debts.
"There is an opportunity every step of the way," Criddle said.
Social networking sites such as Facebook and MySpace also give predators a bevy of clues into the lives and families of users, many of whom believe they have preserved their anonymity, Criddle said.
She pointed to one MySpace profile that itself offers scant details, but also displays three comments from friends who reveal the person's full name, school mascot, age, birthday and details of a pending party.
Criminals also can use personal information to tailor a fake online personality designed to win a victim's trust, Criddle said, using as an example two seemingly innocuous photos from the profile of a 15-year-old girl.
In one, the girl is sitting on the porch. Her haircut, clothing and home indicate she is not wealthy and may be attracted to "bling," Criddle said. Her body language - open, but with tense shoulders - suggests she is new to social networking sites and may be an unsuspecting victim.
A second photo shows a man who appears to be the girl's father, which suggests he is an important part of her life. To a financial or sexual predator who wants to get close to the girl, that signals that "playing the daddy roll is not effective," Criddle said. The photo also shows a city flag in the background, and the porch photo shows her house number: 101, almost certainly an address at an intersection, Criddle said.
The conference continues today with a presentation by Chris Hansen, correspondent for "Dateline NBC."