The ways of the world are in constant flux. What was commonplace is now superseded, no more so that in the recent BA saga.
For years the ancient maxim to regain control of an errant computer was to switch it off than switch it back on again; such advise generally given by a chap on the help-desk in India. Yet BA now advise this was the very reason for the massive computer shut down over the bank holiday.
Apparently a man in a white van popped into their computer control room near Heathrow, pulled the plugs out of the computer to boil his kettle for a cuppa and the emergency back power supply into his toaster. Then after his break put the plugs back into the computer and went on his way.
The computer was only half way through shutting when it was switched back on again. The software then met itself in the middle, attempted to mimic the Hadron collider by smashing things into each other at high speed and the rest is history.
I love the explanation given by the techie guy at BA when the computer was switched off – “This resulted in the total immediate loss of power to the facility, bypassing the backup generators and batteries. This meant that the controlled contingency migration to other facilities could not be applied”. Basically he means “it all went tits up”.