"What you guys have to think about is, how much information do you put on your social networking pages?" McGuire says to the assembled students.
McGuire is not a teacher. He's a prosecutor who goes after online sexual predators. But he also works hard at keeping these students at Moody Middle School -- and at other schools across the state -- from becoming victims, reports CBS News correspondent Thalia Assuras.
"You all will talk to somebody online and then want to meet them in person. And that scares me to no end," McGuire told the class.
It's this generation's "scared straight" -- the 1970's effort to keep kids out of trouble.
So many today are so computer savvy that Virginia now requires every public school student get lessons in online safety, starting in kindergarten. It's the first state law of its kind.
"We realize that it's a public safety issue, because we see the increase in Internet related crimes -- dramatically in Virginia," said Bob McDonnell, Virginia's state attorney general.
"One out of 4 kids aged 10 to 17 will receive at least one unwanted sexual solicitation during those years, and only 1 in 4 of those will tell their parents," he added.
The number one reason they don't tell is because they're worried their parents are going to take the Internet (away), so to them it's not in their best interest to tell their parents," says McGuire.
With kids often more computer capable than their parents, schools across the country are making Internet safety part of the lesson plan.
"Does everybody here know more about the Internet than their parents do?" Maryland Attorney General Doug Gansler asks a group of third graders.
"Yes!" they all agree.
In Maryland, third graders learn about online do's and don'ts with the help of cartoons.
Rusty McGuire knows that kids often believe they're invincible and don't realize that what they put online can be accessed by anyone with a computer.
McGuire's job is to teach them rules for how to stay safe -- and the kids are listening.
Asked what the most important thing he learned in the day's lecture, eighth grader Dewi Smith says, "Not to give out your full name on the Internet, because it's forever and they can find you."
Classmate Tyra Beamon, agrees "I'm sure many of us will still keep our MySpace accounts, but I will definitely change some of my, like, I'll set it to private and change those things."
Among the top cybersecurity tips for parents: keep your computer in a central location in your home, and be aware of other computers your children may be using.