> we should never expect that it is reasonable to conduct mass surveillance on all the roads in the country to find out where people go all the time.

Utility and traffic light poles have cameras and license plate scanners that can capture up to 5000 plates/sec, even in smaller suburban areas, at an increasingly alarming rate.

EZ Pass and similar are scanned in lots of places that aren't toll plazas — at least that is possibly agreed to via a terms of use.

These are facts but they don't answer the question "Why do people think this kind of stuff is reasonable and positive for society?"

Because it solves crimes.

I was on a jury where the police were able to track down a hit and run driver who killed a teenager within about 45 minutes due to red light cameras.

There are lots of things that we could do to solve crimes but we don't because of the negative effects of doing them.

Torture is a good example.

Torture is not a good example. If you torture someone enough they will tell you whatever you want them to tell you in order to stop it.

Mike Baker talks about why it was pointless for the CIA to torture someone and why when they train people how to handle being capture, they tell them to tell the truth with a little information redacted.

Solving crimes is a minor bonus for society. If they had prevented the driver from killing the teen, then that would have been a much more compelling argument. But people running after a fatal crash doesn't make situation much worse, and the incentive to avoid fatal crashes doesn't change massively if you know for sure that you will be caught rather than being almost entirely sure.

In most of the comments about solving crime, its never about prevention but rather retribution.

Can't they already track people that way using car or phone gps?

That depends on who controls the software running on the car or phone. Determining your position via GPS does not emit any signals that can be detected; it's a purely passive process. If malicious software installed on the phone records the GPS data and later transmits it, then yes.

However, cellphones in particular do require the cellphone network to track at least which cell they're in in order to work, so in practice controlling a cellphone network gives you a pretty good idea of where all the subscribers are.

This is a big problem, and we need to figure out how to stop it if we are to enjoy the sort of freedom from government surveillance that people everywhere enjoyed since the Paleolithic until about 01998. The 20th-century results of giving too much power to governments are not promising.

Something doesn’t become a good thing just because it’s possible and/or been happening for a while.

In general, it becomes a good thing if it helps more than it harms.

Yes, they can.

"Reasonable" changes over time, with available technology, and with the tolerance of the public. People don't much care for "We could've stopped that murder / caught that murderer, but we didn't use the resources available."

If there's a murder on a street corner, do we expect the cops to not pull camera records from every nearby store with an outward-facing camera?

In my experience, cops won’t do any detective work anymore unless it directly affects them. Your house is broken into and the thieves dropped their wallet with their ID? The cops will not follow up on that and get your stuff back. Murder? Hardly.

Murder and theft are treated very differently (but yes, theft is under-prosecuted... The police are under-incentivized to pursue it because insurance usually makes the victim financially whole).