A health educator says the young men involved in the "Roast Busters" group are performing the kind of behaviours they see in pornography.
The director of health promotion for Family Planning, Frances Bird, says this case comes as no surpise. She says while it is concerning, it's not unusual, either in New Zealand or overseas.
She spoke to Radio New Zealand's Kathryn Ryan. (A warning, some of the content in this interview could be upsetting.)