"If you get the monitoring software, put it on the computer and forget that it's there," Aftab says.
Cyberbullying includes sending hateful messages or even death threats to children, spreading lies about them online, making nasty comments on their social networking profiles, or creating a website to bash their looks or reputation.
Cyberbullying differs from schoolyard bullying, Handy says. "When it happens online, there's no one to filter it," she says.
But instant messaging, chat rooms, emails and social networking sites can also bring trouble - from cyberbullying to more serious Internet dangers, including exposure to sexual predators.
How savvy are you about keeping your child or teenager safe online?
In the age of You Tube, a website that hosts videos shot by users, "Kids are looking for their 15 megabytes of fame," Aftab says. If it's a one-time thing, try to ignore the bully and block future contact, she says.
"They do it to show that they're big enough, popular enough, cool enough to get away with it." Often, kids don't tell parents they're being cyberbullied; they're afraid their parents will overreact or yank Internet privileges, Aftab adds. But if the cyberbullying involves any physical threat, you may need to call the police.
"Think before you post, because once you do, it's going to be up there forever," Shehan says.
A child's online reputation is a growing concern, Aftab says, with the rise of online social networking and profiles.
More predators are now scouring social networking sites, such as My Space and Xanga, because these sites have centralized so much information, Shehan says.
A child's profile typically includes photos, personal interests and blogs.
The Cyber Tipline helps prevent sexual exploitation of children by reporting cases of kids enticed online to do sexual acts.