Researchers at Context Information Security have demonstrated that it is very easy to monitor IoT devices that implement the Bluetooth Low Energy protocol. The team demonstrated how easy it is to monitor and record signals transmitted by IoT devices, including mobile phones, wearable devices, and iBeacons. Among the devices analyzed there are the popular iPhone and a number of the leading fitness trackers. The researchers have also developed a proof of concept Android app, dubbed RaMBLE, for scanning, logging and mapping Bluetooth devices.”]
Source: http://securityaffairs.co/wordpress/37149/hacking/tracking-bluetooth-low-energy-devices.html