i've been thinking a lot about this piece the last few days (and worrying) https://www.nytimes.com/interactive/2019/12/21/opinion/location-data-democracy-protests.html

Seasoned protesters turn their phones on airplane mode or turn off location tracking on all apps. But obviously the size and scope of these protests means there are many heading out who won't do this. Commercial apps of all kinds will be tracking & storing their movements.

It's easy to see how this could get very grim. This location data is out there...it's bought/sold/traded to marketers. Political campaigns are some of the biggest marketers out there. They're hiring companies that collect this kind of data. Once they have it, they have it.