Arthur C. Clarke said this quote
“ That requires as much power as a small radio transmitter--and rather similar skills to operate. For it's the application of the power, not its amount, that matters. How long do you think Hitler's career as a dictator of Germany would have lasted, if wherever he went a voice was talking quietly in his ear? Or if a steady musical note, loud enough to drown all other sounds and to prevent sleep, filled his brain night and day? Nothing brutal, you appreciate. Yet, in the final analysis, just as irresistible as a tritium bomb. ”