Smartphone owners typically disable location access in device settings, if not needed, so that applications and web services can not locate the user through GPS, mobile phone networks, or wireless WLANs.
However, this procedure does not mean that the smartphone can not be located from the outside; anyone who wants to be unable to know its position or its movement data (offline tracking), turn off WLAN and Bluetooth, when it does not need this Wireless functions.
According to Deutsche Presse-Agentur, when a WLAN is effective, the smartphone automatically transmits the uninterrupted serial number of the wireless WLAN module, known as the MAC address, and sends a similar number of Bluetooth enabled units, which can The time to receive signals from Bluetooth transmitters (Beacons), companies may exploit these numbers for interactions or so-called offline tracking.
With the numbers being transferred and the signals received, the smartphone owner's path in a store, a pedestrian area, or the entire city can be identified or identified in a particular location, as well as the launch of actions for applications installed on the smartphone or showing ads In a targeted manner.