Almost everywhere you go today, you can find "free" Wi-Fi, from restaurants to malls to airports to open access in cities. Most people don't think twice about connecting to free Wi-Fi to avoid data overage charges, especially streaming media. Click, connect, accept, and off you go.
The dark side of Wi-Fi is that your smartphone can be used to detect your presence, how long you linger, and where you move about in a room, building, or space.
Even if you never connect to the "free" Wi-Fi.
This is done through Wi-Fi management frames called probe requests. Frames are transmitted at regular intervals, as long as the Wi-Fi on your smartphone is enabled, and they can be used to identify your presence, the time you spend somewhere, and if you're a repeat visitor.
Yes, Wi-Fi remembers you (actually, the device you have on your person).
Using the signal strength from your smartphone, Wi-Fi access points can triangulate and determine where in a room or building you are, if you're moving about, what entrance you used and what kind of device you have.
Sure, there are lots of business use cases to know this kind of detailed information. Wouldn't a business WANT to know how many people walk into their establishment? Or determine staffing based on traffic? Or tell how many people show up after a sale is announced? Or see what locations loyal customers visit and target ads and coupons to them? The list of intelligence is extensive.
These analytics and capabilities, however, are not new. Wi-Fi access point manufacturers such as Meraki and Aerohive have baked these capabilities into their equipment for years and through API's, make the analytics available to customers (not the consumer like you).
Most of these Access Points can detect Bluetooth devices as well, like your Apple Watch or Android Smartwatch.
That's all if you never connect to a free Wi-Fi and just wander around with your smartphone's Wi-Fi enabled. Once you connect, you've opted-in and your identity is associated with your devices. Forever.
You're thinking, I don't connect without a VPN on my device. That's a false sense of security because your device still puts out probes that can be used to locate and remember you. Using a VPN does nothing to prevent this type of tracking.
Most people probably don't care. After all, Equifax leaked everything anyway right? But for your privacy, you SHOULD care. As 802.11 technology continues to evolve, the depth of the analytical capabilities will increase even more, getting more invasive or "feature-rich."
You have to ask yourself, what's your privacy worth?
What can you do? Contact Firestorm Cyber for tips.