TUESDAY, May 31 (HealthDay News) -- As the school year wraps up, many kids will replace class time with cyber time -- a trend leading one researcher to caution parents to watch out for online hazards such as "sexting" and cyberbullying.

"The Internet is a vast place with great things on it for children like games and educational lessons, David Schwebel, a psychology professor at the University of Alabama at Birmingham, said in a university news release. "There also are risks and danger such as sex crimes, violence, hatred and prejudice -- a lot of things children need to be protected from."

Schwebel points to a recent Pediatrics study that revealed about 75 percent of teens have cell phones and nearly a quarter of all American teens (22 percent) are surfing a social media site more than 10 times per day.

"Parental controls can help, but are not foolproof," Schwebel noted. "Parents need to teach children to act safely and get help when needed."

To that end, he outlines a number of tips designed to boost cyber safety among school children.

For one, Internet activity among young children should be routinely monitored, he advised. Parental participation in their child's web-surfing activities is a way to teach kids how to distinguish between appropriate content and inappropriate content, he suggested.

In addition, pressure to join in common Web activities (such as posting overly personal photos) should be a topic of conversation between parents and child, so that children feel empowered to resist such temptations.

Parents should also be on the lookout for signs that their child is being unsafely drawn into cyber-prompted activities, such as arranging to meet strangers they've talked with online.

Lastly, Schwebel encouraged parents to put time restrictions on cyber activities. "Sitting on the Internet does not burn calories," Schwebel said. "Children need to be out running, playing and active."

More information

For more on cyber safety for children, visit the U.S. American Academy of Pediatrics.