It's funny that this is coming up now. The other day I was on the phone with Geico's roadside assistance and they wanted to know my location. I told them I didn't have their app downloaded, they said it wasn't a problem and they could get it without it. Sure enough they could. I checked their disclaimers [1] and they purchase the data from my cell carrier. They didn't even have to know which one.
[1] https://www.geico.com/web-and-mobile/mobile-apps/roadside-as... (see disclaimers at the bottom)