I don't find the locks on the doors to be a bad thing as it does reduce the amount of people using it as a shortcut, although many still do take these shortcuts, one I often see is people coming from outside and running across the road and entering through the doors for offloading passengers on the X66 stand.
I think they want to get the message across by being tough on this as I think if they talked to most people in a nice polite way they may not bother listening to them although others probably wouldn't respond to being shouted at.
They clearly are trying to prevent another incident like the 1213 incident happening again.
RE: Transport Photography