Stopping passengers taking their bags is a matter of raising awareness beforehand, so that the majority of passengers know about it, and will not be surprised when asked to do so in a moment of extreme stress. If old Granny Stumbleshoes wants to take her knitting from the overhead locker or Mr Smartarse Executive feels his computer is more important than a person at the back of the queue, then neither of them are going to give in quietly when the cabin staff tell them to leave their stuff and get out and under those circumstances it makes sense not to argue since it will waste time. But if all passengers were made aware right from the outset that they might be required to leave everything, and the reason why, then we might at last start to make an impact on the problem. As has been said many times, you can’t predict what people will do in panic, but the more familiar and consistent the message, the more likely it will be heeded. At the moment there isn’t any message.