It stand to reason that everyone has an opinion. It also stands to reason that every now and then, everyone wishes to express their opinion. And sometimes, everyone wants to express their opinions all at the same time, as loudly as possible. Thus begins a shouting-free-for-all.

This is a situation where an entire room is in an argument; people are shouting and yelling, sometimes on their feet, getting into each other's faces, and the whole situation drowns out the points anyone is making (if they're making any points at all), and renders any form of debate practically useless.