FWIW you almost certainly can at minimum generalize the location of a phone if you know roughly where to look via beamforming [0]

Massive antenna arrays and SIGINT satellites have massive funding and decades of history, and they've already shown interest in tracking literally everything else [1]

This isn't some star trek type of thing, this is a "would the USG dump enough money into SIGINT to implement it?"

I'm very confident the technology exists to roughly track specific locations of interest for specific devices if not more.

I understand people may disagree but it would be foolish to assume it's beyond the realm of possiblity.

[0] https://space.stackexchange.com/questions/55143/is-it-possib...

[1] https://www.aerosociety.com/news/eavesdropping-from-space/