From the news - which, yet again, gets their stories off YouTube. Again with the Aussie schoolgirls!
Girls pick fights, allegedly in order to get suspended. But what should be done - the fights occur outside school grounds and hours. Personally I am cynical about the effectiveness of suspensions in changing behavior - the punishment part is when the police are involved.
Possibly the school could require that the students be dropped off and picked up at the gate, and escorted around the school grounds? But look at the manpower involved, and a personal minder would just be an extra bit of notoriety. So basically it is lose lose no matter what. Suspension + Police removes the student from the student body (thus somewhat protecting likely victims) while they come to grips with the seriousness of the offense.
So the responsibility ends up with the students and how the police handle things.
There is also the question of why these students would choose this method to buck for a suspension. I suspect teenage risk-taking and bravado - teens seldom think past the immediate results.