Why are there no cameras allowed at BDI?

The rule regarding cameras is basicly for copyright and player protection purposes...

Any images taken become the property of Shafted Lan.

Can i just ask how shafted can atomatically take over copyright of a photograph as i am studing to be a photographer and id like to know how by law this happens as i am finding it impossibe to belive that such a thing can happen as the photographer in australia automatically ownes copywrite to their image unless its not "moral" and / or it is a portaight (eg: swim suit modle) then you need a modle release to transfer copyright so therfore, wouldn't it be impossible for shafted to do that with out a signed release of copyright ? to make it simple you could just ban cameras ?
here is all about copyight :)
http://www.copyright.org.au/PDF/InfoSheets/G033.pdf
Its a very sticky subject this copyright law stuff so can i ask nicley of course :) What is the legal grounds of this automatic stealing of copyright ?

I have seen people take pictures befor at shafted events.

guessing they would not mind at all if u took pictures for personal use with out asking them.

but

if u want them on a web site or published i am sure the pictures would have to be cheeked by them to make sure it dose not hold any thing that could get shafted in trouble.