I think you are forgetting the difference that computers make. Forty years ago, or even five or ten years ago, there was no way to make use of the information supplied by mass passive surveillance. Now, with increased computer power, universal use of credit/debit cards and mobile phones, CCTV cameras everywhere, traffic cameras, face recognition software, number plate recognition cameras, and the proposals for all vehicles to be "chipped" and for everyone to carry an identity card with a transponder, the mechanisms are in place for a "big brother" system which Hitler or Stalin would have given somebody else's right arm for.