PC Mag: “Your smartphone constantly checks available Wi-Fi nodes, looking to reconnect with any that you’ve used before. You can see it happening, and it’s very convenient (though vulnerable to spoofing and “evil twin” attacks). What you don’t see is that your smartphone also uploads identifying details about your router to giant databases maintained by Apple, Google, and others. These databases benefit you (and everyone else) by fine-tuning your device’s GPS location skills. We’re here to explain why you might not want to participate and show you how to opt out.”