A phone’s MAC address enables persistent third-party tracking unless the app randomizes it

Evidence

The team also examined the trackers’ transmission of the Bluetooth Media Access Controller or “MAC” address that is unique to each phone. When this address is publicly discoverable, any third party with an interest in your movements—retailers who want to know your mall activity, insurers concerned about your compliance with an exercise regime—can “persistently” track your phone. Multiple data sets logged over time can be combined to form a fine-grained picture of your movements, enabling targeted applications and heightening the probability of guaranteed outcomes. The only real protection is when an app randomly but regularly generates a new MAC address for your phone, but of the nine trackers, only Apple’s performed this operation. — Shoshana Zuboff, The Age of Surveillance Capitalism, 778

Categorization

• XREF: Connects to the broader surveillance-capitalism extraction mechanics Zuboff lays out throughout, and to The Soundscape’s treatment of how ambient signals become monitorable data.
• CANDY: Fun fact for a tech-interested friend: nearly every fitness tracker leaked a trackable MAC address except Apple’s.