Per Capita is probably the wrong metric to use here. This isn't just limited to cameras but you don't need a single camera to track a single person. The more population dense an area is the higher efficiency a single camera can have.
Just think about it in this manner. If you have a house and you set up cameras that monitor every square inch of the house, does it matter if there is one person in the house (high camera per occupant) or many people in the house (low camera per occupant)? Obviously not. The US is also one of the least population dense developed nations.
Not that we shouldn't be worried about surveillance, but let's use good metrics.
Fair enough. I didn't find a ready source on average camera densities by country, but comparing cities at the link below can give a sense of the difference. London has 399 cameras per square kilometer. Beijing has 278. NYC has 26, so not quite as Orwellian, in terms of cameras at least.
Approximate Populations, per wikipedia, for reference:
London: 9 million
Beijing: 21 million
NYC: 9 million
Just think about it in this manner. If you have a house and you set up cameras that monitor every square inch of the house, does it matter if there is one person in the house (high camera per occupant) or many people in the house (low camera per occupant)? Obviously not. The US is also one of the least population dense developed nations.
Not that we shouldn't be worried about surveillance, but let's use good metrics.