Friend who also works in tech industry, forwards me a video which explains how Google tracks is users via smartphones. Further calls me and explains it passionately. I'm like ..... wtf. Living under a rock or what🙄

@hube I think I do. They collect the GPS locations of phones whose GPS were on when they came in range or connected to that wifi. Over time they have a database of wifi APs(BSSID) and their GPS location. So if any other phone comes in the range of same wifi, then they know it's location, even though it's GPS may be off