MakeUseOf: “I treat Bluetooth like a light switch. I turn it off when I don’t need it, and assume it’s gone. You did too, right? Turns out, we’re wrong. When you’re not actively connected to anything, your phone is still talking, constantly, to anyone nearby set up to listen. Your Bluetooth signal isn’t really turned off. Instead, it’s advertising your smartphone, broadcasting identifiers, and in some cases, actually connecting to tracking systems you’ve definitely never agreed to be tracked by…I think most are familiar with the concept of a Bluetooth connection. You enable Bluetooth on your two devices, hit pairing mode, and make a connection. It doesn’t always work seamlessly, but for the most part, Bluetooth is super simple to use and does the job. The only issue is that Bluetooth is often broadcasting more than you realize when you’re not connected to a device — and at times, even when you’ve hit the Bluetooth toggle on your device. That’s because when you disconnect your smartphone and your headphones, Bluetooth doesn’t just “stop.” It keeps broadcasting small packets of data containing the device Bluetooth name, a MAC address for unique device identification, Bluetooth profiles supported by your device, and, in some cases, phone specs and more…”