Some stores and other locations look for devices with WiFi or Bluetooth turned on to track your movements while you are within range.
Turn off WiFi and Bluetooth when not in use if you don’t want to be stalked. It would be best if you used a VPN all the time to limit what is compiled on your dossier. To understand why you should use a virtual private network (VPN) click on the link for an article from PC Magazine.
~Network Paladin
