Companies aren't just tracking you online; they track your movements in stores, airports and other locations. This is done using the unique Wi-Fi or Bluetooth MAC address from your mobile gadgets.
So, what can you do? Well, the simplest way to stop it is to turn off your Wi-Fi or Bluetooth when you're out and about.
Of course, if you're using a Bluetooth headset or you're trying to conserve your cellular data plan by using Wi-Fi, that will be tough. Fortunately, there's another option.
The Future of Privacy Forum has set up a site called Smart Store Privacy. You can put in your Wi-Fi and Bluetooth MAC addresses and it will tell participating tracking companies that you don't want to be tracked. Right now there are 12 companies signed on.
Not sure what a MAC address is? Learn how to find it on your gadget.