Apple and Wi-Fi Positioning System: Predicting the Future of Location Data

Apple and the satellite-based broadband service Starlink recently responded to the security and privacy implications of how their services geo-locate devices. Researchers from the University of Maryland utilized publicly available data from Apple to track billions of devices globally, including Starlink systems, to monitor the destruction of Gaza, movements of Russian and Ukrainian troops, and more.

The way Apple collects and shares information about Wi-Fi access points allows its devices to have an alternative low-power option to constantly requesting GPS coordinates. Apple and Google run their Wi-Fi-based Positioning Systems (WPS) that collect hardware identifiers from wireless access points. Both record the MAC address and BSSID of the Wi-Fi access point. Apple's WPS returns geolocations of up to 400 BSSIDs that are nearby the requested one and uses around eight of them to determine the user's location based on known landmarks.

Through extensive research, it was theorized that the verbosity of Apple's API could be used to map individual devices' movements in virtually any defined area worldwide. By analyzing data between November 2022 and November 2023, researchers saw a global view of more than two billion Wi-Fi access points, except in certain areas like China and parts of Australia and Africa. The extensive data also allowed monitoring of Wi-Fi access points in active conflict zones like Ukraine, revealing the movements of Starlink devices used by Ukrainian and Russian forces.