PARANOIA. You can't turn the lights back on without a schematic. The schematic for Baghdad, apparently, was so top a state secret that nobody dared draw one. Or so this Photon Courier post suggests. (The big challenge a power grid operator faces is balancing load with supply, instantaneously. Too much load relative to supply and safety breakers open up. Too much supply relative to load, and where does it go? And if you turn a generator on, and you don't know where the power is going, all sorts of grim things can happen.)