New submitter cryptizard writes: Modern Android and iOS versions include a technology called MAC address randomization to prevent passive tracking of users as they move from location to location. Unfortunately, researchers have revealed that this technology is implemented sporadically by device manufacturers and is often deployed with significant flaws that allow it to be easily defeated. A research paper [published by U.S. Naval Academy researchers] highlights a number of flaws in both Android and iOS that allow an adversary to track users even when their phones are using randomized MAC addresses. Most significantly, they demonstrate that a flaw in the way wireless chipsets handle low-level control messages can be exploited to track 100% of devices, regardless of manufacturer or operating system.