It took computer safety expert Linda Criddle only nine minutes to snag the phone number of a teenage girl in Nebraska who had posted just a little information about herself on a social networking Web site.

Criddle is a former Microsoft employee who specialized in online safety and is the author of a consumer-safety book, "Look Both Ways: Help Protect Your Family on the Internet."

She spoke at the Economic Crime Conference sponsored by the Utah Attorney General's Office on Thursday — with a message that would send shivers down any parent's spine.

Criddle said social networking sites, such as FaceBook and MySpace, can be useful tools, as are other things such as online banking and shopping, which she uses regularly. But she strongly urges consumers to protect themselves with the best safety software available and to be extremely cautious about revealing personal information.

Criddle on Thursday focused primarily on how criminals profile victims through the Internet. The Nebraska teen, Brittany, offered a sobering example.

The girl offered scant written material but posted two photos that could be a road map for crimes —

not only for sexual predators but also for other types of criminals. The first showed a young girl sitting on the porch of her house. Another photo showed the view from her home, with a car and her father in the foreground.

What's the problem?

Criddle pointed out that the girl's socioeconomic status could be determined by the house, car and the child's manner of dress; the house address numbers were visible; the view from the house showed an easily identifiable business; and a railing suggested an older person might live there.

Thieves might want grandma's valuables. Someone could stake out the house from the business across the street and burglarize it. As for Brittany, what little data she provided was enough to reveal a somewhat lonely and naive youngster who lives in a small town and is trying to seem cool by talking about how she's not really the goody-goody type and loosens up with a bit of booze.

"What self-respecting teenager uses a word like 'booze'?" asked Criddle, who has four children. "When she says, 'I am not an angel,' that tells me that she is."

Since the girl's father is in the picture, clearly a sexual predator could not try "grooming" the girl for sexual exploitation by filling in a paternal role, but since the family obviously doesn't have much money, perhaps Brittany could be enticed by consumer goods. Criddle contacted the teen to urge her to change her Web posting.

Other teenage sites showed that even young people who are careful about giving out information can be undone by their friends' indiscretions, including one girl whose friends in their posted comments mentioned her name, the location of her 16th birthday party, a cell phone number and the fact that various parents would be out of their houses at certain times.

Criminals also check out bridal and baby registries, where identity theft can occur even before a child is born, and obituary sites, especially those that include genealogical information.

Another source of concern is surveys and games.

Criddle once, as part of her work, plugged fake information into a health survey on longevity that kept asking highly personal medical questions, which was followed by a health insurance survey that wanted financial data. She noted that her information was being fed in real time to a giant retail pharmaceutical firm that wanted to sell her products and it also was going to other, unnamed sites.

"I wasn't finished with my first survey before I got my first spam (e-mail)," she said.

Schools and government agencies also can unwittingly provide far too much personal information that could be risky, including one community she discovered that keeps mortgage information — including Social Security numbers and financial data — posted with property records.

Criddle's message clearly resonated with her audience.

"I deal with this stuff all the time," one member of the Utah attorney general's staff said during a break, "and she scares me."