In surveillance and police states like The Netherlands it has been used since forever:

https://www.theguardian.com/cities/2018/mar/01/smart-cities-...

Now people will say again that this project has been abandoned, which just isn't true (2024):

https://www.dutchnews.nl/2024/06/smart-street-surveillance-o...

I was watching a crime solving show from the UK. A huge percentage of the crimes are solved using camera footage. Also, they use geofencing, looking at which phones went in and out of the crime location at the time of the crime.

	▲	fy20 6 hours ago \| parent [-]
		I would be surprised if this hasn't existed for a few decades already. Back in 2009 I was working at a place where O2 was a client, and they gave us an API that could identify the cell tower (inc. lat/lng) any of their customers were connected to. The network needs to track this data internally to function, so the API is basically the equivalent of their DNS.