Yes, that is correct. However, inside these estates the houses do have additional electric fences and has often not got walls around the house. The estate is surrounded with palisade fencing that is electrified and we have about 15 armed guards that patrol the estate. The vehicles are equipped with infra-red night vision and we have cameras on the perimeter of the fence. We still do not sleep with our doors open. We also have boom gates through which you enter with your finger print. The security company has now got a helicopter in case of an unlawful entry through the fence. Having the helicopter is new, however, that is if you have fuel to run it on. In the case of a grid collapse, no electricity to run the electric fence with, no fuel for the helicopter etc etc. So not having electricity is putting you at a very big disadvantage.