How your WiFi setting is used to track you

Tracking happens not only when you’re actively browsing the web, but all the time. Some tracking methods used are really subtle and usually not noticed. Have you ever wondered how your phone automatically connect to your home network as soon as you enter your house? Your phone is constantly sending out signal in the quest of a known network. Your device is basically communicating with all nearby WiFi networks without taking a break. This communication is not restricted to known networks, but it happens with all networks.

The information that is shared with a network contains data about your phone but also a list of all networks known to your phone. Most users have connected with a lot of networks in the past. The combination of all these networks is almost unique for each of us and acts like the fingerprint of your device. This unique fingerprint is sent to all nearby networks and can be used to track you in real-time.

If you are in a mall, at the airport or simply moving around in your city, many routers belonging to the same network see your phone’s signal. This allows to follow your path very precisely. It is possible to see where you’ve been, how long you spent in a shop and when you take a break. This is valuable information when it comes to analyzing people’s behavior in order to better place advertising, decide a new shop’s location, or send location specific offers.

There are different ways to fight against that.

The first and simplest trick is to turn of WiFi when you’re not using it. Make sure to turn it off in the settings and not just from your Control Center as this doesn’t completely deactivate the WiFi signal.

Reset your network settings regularly. Each time you connect to a new network, your fingerprint gets more unique. Regularly resetting your network settings removes all WiFi network, VPN connections and restores the default settings. You will have to reconnect to your networks and reenter the passwords. However, it is worth it to do some housekeeping now and then.

The last trick is more advanced but very effective. Use a Faraday cage. A Faraday cage physically blocks all incoming or outgoing electromagnetic waves. As soon as you put your device in a Faraday cage, it becomes completely isolated from the outside world and cannot send or receive any signal. You can buy different kinds of sleeves depending on the item you want to protect. Sizes range from small for credit cards and passports to entire bags.

So next time you are on your way, there might be someone tracking your way around town by looking at your WiFi signal. Just try one of the tricks to remain unobserved.