AS Australia recognised the National Day of Action Against Bullying last week, Kiama High School called on parents to keep a closer eye on their children's social-media habits.
Acting principal Darrell Sheppard said cyber bullying had crept up on schools throughout the state in the past few years as social media became more widespread.
He said small groups of Kiama students were creating Facebook groups excluding another student, allowing them to exchange comments about that student.
"They put things on there thinking that they're not going to see it, but then they share passwords and the student gets to see it and is extremely hurt by it," he said. "We've also seen cases of students taking photos of other students without their permission ... and writing a caption insulting the person.
"It's awful stuff."
Mr Sheppard said the culprits tended to be female and in the more senior years.
Reports of cyber bullying tend to be concentrated after school holiday periods, taking deputy principals' hours to investigate and discipline.
"That's time they could be spending implementing a new program for the school or helping a student who's struggling," he said.
"But from the cases we've seen this year, everyone's stopped doing it."
Mr Sheppard said the school actively encouraged students to avoid cyber bullying. This included Lake Illawarra Police school liaison officer Senior Constable Kerryn Mura regularly visiting to talk about the legal implications of cyber bullying, covering the topic at fortnightly meetings and offering welfare programs to students in need.
"We need parents to be really vigilant," he said.
"In some cases, we get anonymous letters with a copy of the Facebook page for us to act on it."
Kiama Public School held a cybersmart presentation for parents last night.