It's collected by every Android device on the planet which has background scanning enabled. Have neighbours? Have WiFi? Neighbour has GPS on? They can GPS pinpo

It's collected by every Android device on the planet which has background scanning enabled. Have neighbours? Have WiFi? Neighbour has GPS on? They can GPS pinpoint your WiFi by signal strength between the devices that "see" it, then correlate that with the GPS from the devices that are allowing it. I moved home a few years ago, just 200M away, my location in GMaps, when on WiFi remained at my old address 200M away for a good year (I moved my AP with me and kept the SSID).