If your cell phone isn’t in your hand this second, it’s almost certainly within reach. If you’re like most people, it rarely leaves your possession; you carry it everywhere you go.
And that is precisely how Google knows where you are at all times.
Far above their proficiency at making phone calls (who even uses them for that, anyway?), smartphones are excellent at collecting data about the world around you – and therefore, about YOU – even if you don’t tell it to. Almost everyone who has a smartphone has, at some point, used it for navigation, so you’re probably familiar with the interface. Tools such as Google Maps are frequently updated with new roads, up-to-the-minute traffic conditions, delays, etc., making it a vital tool when traveling. But where does all that information come from? Yes, your smartphone.