Apple is preparing to shut down a trick that companies you’ve never heard of have been using to gather information about your shopping habits.
Unless the Wi-Fi capability of a phone is switched off, it is constantly sending out signals, looking for a way to connect. These signals include a unique identification number for your phone called a MAC address. Companies such as Euclid Analytics and Nomi realized they could set up hardware in retail stores to collect these pings, analyze the patterns, and sell what they learn to the retailers. Because people never connect to these networks, a company like Euclid doesn’t even have an opportune moment to ask for permission.