Earlier quoted context omitted.
> I’ll be pretty shocked if I’m “spied on” with this style of device. Why? There's plenty of devices in the wild constantly looking for wifi connection attempts, BLE Scans. Even cellular provider track locations in real-time by logging what cell towers you're using and associated signal strength. Just search for a place in google maps, and note the "Popular Times". How do you think they got that data :D
Um they get that data from being a monopoly and knowing when most people are looking up directions to or information about a location. Sure, they might do some other stuff to expand the data but there's much more relevant data right in their first-party domain.
The same way traffic readings are done, not by cars, but by people in cars with phones.