The Secondary Principal's Association says the emerging problem of sending texts of a sexual nature in high school has led to some schools banning cellphones in changing rooms.
The schools are worried that students may use their phones to take pictures or videos of themselves or others in states of undress and then send those images to other people, in a practice known as "sexting".
Association President Patrick Walsh says intimate photographs are usually sent between boyfriends and girlfriends.
However if the relationship breaks down, the images are used as weapons against the former boyfriend or girlfriend and sent to others.
Mr Walsh says nearly every high school has a policy on mobile phone use and some have taken the extra step of requiring students to give their phones to teachers before they go into changing rooms.
Avondale College Principal Brent Lewis says the school has a blanket ban on cell-phone use during class time, which includes changing rooms.
He says the school has not dealt with "sexting" specifically but has talked about the intrusion of taking someone else's photograph.
The Secondary Principals Association says it is unfortunate that parents are often oblivious to these issues and from time to time they should check what is on their children's phones and computers.
