This is a subject close to my heart.
Many years ago I worked in a university residential college. The students there were attending a campus specialising in rural, agricultural and agronomic studies.
Some of these students were certificate students, so they were under 18 (the age of majority in Australia). The college principal, staff and residential staff had a duty of care to these youngest, and a responsibility to their parents/guardians to ensure that they were not in danger, moral or otherwise, at the college. Some of the adult (read over 18, under 25) students disliked the restrictions placed on them to protect the younger residents.
There were things which happened on the campus which were stupid. Students took risks. It was almost impossible to get through their 10foot tall and bulletproof attitudes that there were some foolish and risky things that they should not participate in or encourage.
Things like the common practise of riding on the back of a tractor just for transportation, or travelling in the back of a utility on the campus roads.
Their come back was "It's a private road, so we can do it, it's not illegal."
Well, it is not a private road. It may not be illegal to do it on a private road, but if something goes wrong there are worse things than dying. And the fact that it's not illegal won't save you from dying or breaking your neck. Ask my cousin who is an incomplete quadriplegic and has been since 1991 when he was only seventeen and sleeping in the back of a moving panel van which was shunted from behind.
Ask these kids and their families...
Update: I have read on the TV crawler that they were rabbiting... let me see, 14 people in a 1 ton ute... three or four in the front. Ten or eleven on the back? Shooting rabbits? With rifles? I don't think so.