On the screen at the front of the classroom, Virginia assistant attorney general Gene Fishel flashed an online social-networking profile of "hotlilflgirl," a 15-year-old who says she enjoys being around boys and wants to meet new people.

The next image revealed the real "hotlilflgirl" — a mugshot of a 31-year-old man convicted of sexually abusing 11 children he met online and sentenced to a 45-year prison term on charges including child pornography and forcible sodomy.

"Not little, not fly and not a girl," said Fishel, in warning teens about the dangers of sharing personal information on the Internet and agreeing to meet Web acquaintances in person.

Fishel's recent presentation at James River High School was one of many being held in classrooms this school year across Virginia, the first state to mandate that public schools offer Internet safety classes for all grade levels. It's one of many measures being taken nationally to protect young Web users.

Virginia's requirement initially stemmed from concerns about sex offenders preying on children online and a general increase in Internet-based crime, including spamming and phishing. More than half of the world's Internet traffic flows through Virginia, as America Online and MCI have major operations in northern Virginia, according to Attorney General Bob McDonnell.

Texas and Illinois are among states that subsequently passed Internet safety education laws, but unlike Virginia, they don't make the courses mandatory. And others are considering similar legislation, said Judi Westberg Warren, president of Web Wise Kids, a nonprofit group funded by corporations such as Verizon and Symantec and the federal government to provide schools with no-cost Internet safety lessons for 11- to 16-year-olds.

The Illinois law recommends that school divisions adopt online safety training curricula and offers guidelines on topics that should be included, said Matt Vanover, spokesman for the Illinois State Board of Education.

Warren said such efforts are overdue as the Internet's technological advances have enabled criminals to reach more victims.

The FBI doesn't specifically track the number of sexual-abuse cases that originate online. But according to a 2006 study by the National Center for Missing and Exploited Children, about 13 percent of Internet users ages 10 to 17 received unwanted sexual solicitations. Ninety percent of those solicitations targeted teens. Four percent of those youths reported being asked for nude or sexually explicit photographs of themselves.

"Decisions to make Internet safety training part of the curriculum should have taken place years and years ago," she said. "Kids are encountering the Internet at younger and younger ages. Society is slow to realize the impact the Internet is having on kids."

For preteens, schools often focus on cyberbullying — which includes harassing, spreading gossip or otherwise targeting others online — and several states have passed anti-cyberbullying measures.

Nine percent of youths in the center's survey reported being harassed online, and 28 percent of youths admitted they "made rude or nasty comments to someone on the Internet."

Tammy McGraw, director of the Virginia Department of Education's office of educational technology, has worked with school divisions to integrate Internet safety lessons into existing coursework. Her office also helps schools educate parents, including encouraging families to use filtering software and put their computers in public areas of the house.

"We're all sensitive that many, many important things need to be addressed. This is absolutely essential," McGraw said.

Under mounting pressure, social-networking site MySpace reached an agreement to create a task force to devise ways to protect youngsters from online predators and bullies. The deal between the company and 49 of 50 states — except Texas, whose attorney general has said he can't support the effort because it lacks a way to verify users' ages — comes as the exponential growth of such sites have created a venue for predators and cyberbullies to lure and threaten young people.

At James River High School, Fishel also warned students about the permanence of what they put on the Internet, and how information posted today can come back to haunt them when they're applying to colleges or looking for jobs. It's basic advice on issues that might not occur to teens who generally live in the moment.

Some listened attentively to the presentation; others slumped forward over their desks.

"I thought it was very important because we post a lot of things on the Internet," said freshman Maya Towers, who created a MySpace page in August. "I didn't know how much information can be exposed."

Others, like 16-year-old Kyle Rackley, still figures that becoming an online predator's victim can't happen to them.

"I feel pretty safe about it," he said.

McDonnell says young people are vulnerable precisely because they think they're bulletproof. No one wants to curb teens from using Facebook and MySpace, he said, but in the Internet age, it's necessary to update all students with the basic warning of "Don't talk to strangers."