An example, measuring traffic flow in a city. You can do it with cameras and ID plate detection tools, which allows tracking where anyone is at any time. You

An example, measuring traffic flow in a city. You can do it with cameras and ID plate detection tools, which allows tracking where anyone is at any time. You can also put magnetic loops into the roads, which just tells you how many drive over a certain area of the road, without any individualized tracking. Good telemetry is like the magnetic loops. But nowadays very few implementations are that privacy respecting