This is a perfectly normal procedure carried out on every aircraft - but what do we get from the good old Daily Mail ?
Passengers were in a state of:- "panic" and "terror", and who were "sobbing and crying" - isn't there a lost kitten story they could cover ?
I've had it happen on a boat ... "will some of the passengers please move to the other side of the boat so that we can keep both paddle wheels in the water"

How about on a train ... "there are too many people sitting in the window seats, and our train manager will be passing through and asking som eof you to move to aisle seats"