A network of CCTV cameras that surveils all public spaces in a city is creepy to most people, even though in practice the video quality and technical ability to make use of the videos are still rudimentary. The prospect of high resolution video coupled with facial recognition software combining into a surveillance network that tracks everyone everywhere except in private homes is way past of what most people would accept as proportional to crimefighting demands.
The installation of automated license plate scanners on police cars is similarly creepy, even though the policemen in the car can in theory read the license plates with their own eyes already.
As a rule of thumb, the less opportunities and chances criminals have to escape the police or to escape a general surveillance, the less opportunities and chances political dissenters have to do so once political dissent was turned into a crime.
The rate of return for crimefighting is dropping badly with ever greater surveillance since few if any arrests will be added by additional surveillance. Meanwhile, adding ever more surveillance may reach a point where a collapse of democracy and liberty - even if only for a minority - may be perpetual since the government would only need a tiny popular support to recruit enough enforcers of its rule based on highly automated surveillance that no-one can escape any more.
Initiatives for more surveillance powers, hardware and personnel tended to originate in the respective bureaucracies that correctly expected a growth in personnel, powers, budget from success with such initiatives.
This may change radically in the future, when a conjunction of consumer technologies may provide the basics for a surveillance state that could be switched on in a day.
Here's an example:
Electric cars with autonomous driving combine the cameras (for awareness of the environment as needed for autonomous driving), the computing power and the power supply (batteries) required to act as semi-stationary surveillance camera systems. Communication over mobile phone networks for software updates, emergency calls et cetera is about to be implemented in almost all cars soon, thus such semi-stationary surveillance camera systems could -whenever parked in the open- report not only indexed license plates, but also indexed faces (facial recognition) - on top of reporting the movement profile, location and identity of the users.
The brave new world of electromobility and self-driving cars could provide an authoritarian government with the ability to turn millions of cars into surveillance devices by an overnight software update. They would only need to add a ban on covering up faces (easily enforced by detecting covered-up faces through the surveillance network) and the surveillance would be complete on and close to roads and streets.
This is not meant as a conspiracy theory; I do not assert that this is or will be done, or that any such plans exist in free countries. It's rather a piece of technological impact assessment.
The scenario above will likely be feasible before a public debate about it and about possible precautions against it would be begun, much less completed.
The defence of freedom and liberty at home is not only a perpetual pushing back against bureaucratic excesses and a whack-a-mole against dangerous idiots; nowadays it also needs to include technological impact assessment and legal-technical precautions.