You already know that advertisers are tracking where you go online, even on your smartphone or tablet. But did you know that retailers, airports and other commercial locations are literally tracking where you walk?
It's called Mobile Location Analytics, and it uses your gadget's Wi-Fi or Bluetooth to pinpoint your location. For example, an airport knows how much time you spent in a shop, moving through security or at the baggage claim. A store knows when you move from one department to another or even linger in a certain aisle. How does it do that?
Every computer and mobile gadget has a unique hardware identifier called a MAC address that it broadcasts via Wi-Fi and Bluetooth. As your gadget comes in range of the various Wi-Fi routers and Bluetooth hubs scattered around a store or airport, the company can tell where you are.
Companies collect this information over time and use it to track traffic flow, line wait times, popular products or aisles, tweak employee work schedules and more. But could they use the information to do something more?
The good news is that on its own your gadget's MAC address tells the store nothing about you. Your name, email and phone number aren't transmitted. At most, it might be able to figure out what manufacturer made your phone.
Most of the companies that handle this tracking have also signed agreements that they won't try to tie your MAC address to any other information they might have about you. Of course, those agreements are voluntary and there are ways a company could identify you if it wanted.
One way is by using the in-store beacons. These beacons use Wi-Fi, Bluetooth or Near-Field Communication to connect with your phone and send you deals on products you're walking past. To receive these deals, however, you have to be running the store's app, or have signed up to receive them. So, there's no real privacy concern.
However, imagine if a store were to combine your MAC address location with a beacon pushing a deal to your phone, and you signed up to receive the deals with your name and email address. It's a simple matter to link that information up with the company's records of your purchase history from your credit card or loyalty card. The store could have a full profile on you in seconds.
Some stores are also playing around with facial recognition. Even Wal-Mart gave it a go for a few months before calling it quits.
Granted, that system was geared toward spotting known shoplifters and required a photo on file to make a match. However, if a company has your name and email address, it's a short leap to get your profile picture from Facebook and spot you as you walk into the store.
Of course, eventually the truth would come out and everyone would stop shopping there. So it's unlikely that's going to happen in the near future.
It doesn't have to be the store that's tracking you either. If law enforcement was doing an investigation and got your gadget, they could technically subpoena records for the gadget's MAC address and learn your movements. Or if the MAC address records were lost in a data breach, I'm sure hackers could find some use for them.
The simplest solution to deal with MLA tracking is to turn off your Wi-Fi and Bluetooth before entering a store. That keeps your MAC address from broadcasting. 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.
We should point out that if you're using an Apple gadget running iOS 8 or higher, it changes its MAC address every time it connects to a Wi-Fi or Bluetooth hotspot. So, a store won't be able to track you because it will look like a new gadget every time. Still, not everyone has a newer Apple gadget.
Fortunately, 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.
Finding your Wi-Fi and Bluetooth MAC addresses is a little tricky depending on your gadget. Here are some general instructions.
Note: You're looking for a 12-digit number like 91:17:7B:82:C2:A5 or 91-17-7B-82-C2-A5. It should be clearly labeled.
For Apple gadgets, go to Settings >> General >> About and look under Wi-Fi Address and Bluetooth. If you don't see an address, you should turn on Wi-Fi and Bluetooth and then check again.
For Android gadgets, every phone manufacturer has things set up a little differently. First, make sure Wi-Fi and Bluetooth are turned on. Then go to Settings >> About Phone, or Settings >> About Tablet.
It might be under Hardware Information or Status. If you can't find it, check your gadget's manual for the precise location.
For Wi-Fi, go to Start >> Settings >> Connections >> Wireless LAN >> Advanced. Look in the MAC field. Wi-Fi needs to be on for this to work.
For Bluetooth, go to Start >> Settings >> Connections >> Bluetooth >> Accessibility and look under Address. Bluetooth needs to be on for the address to show up.
For Wi-Fi, go to Setup >> Options >> Device >> Device and Status Information, and look under the WLAN MAC heading.
On Blackberry gadgets running OS 5 or earlier, go to Options >> Status and look under WLAN MAC.
For Bluetooth, go to Connections >> Bluetooth >> Properties to find the MAC address.