A striking report by Open Effect (https://openeffect.ca/reports/Every_Step_You_Fake.pdf) documented the metadata that is collected by today's consumer wearable devices. In one of the cases they explored, the researchers analyzed the Bluetooth discovery features of different manufacturer's wearable products. The researchers attempted to determine whether the vendors had enabled new privacy features that were designed into the Bluetooth 4.2 specification. They found that only one of the manufacturers (Apple) had implemented them, leaving open the possibility of the exploitation of the static Media Access Control (MAC) address for persistent tracking of a person wearing one of the products. Without the new privacy feature, the MAC addresses never change, creating an opportunity for adversarial tracking of the devices people are wearing. Frequent updates to a device's MAC address limit an adversary's ability to track a device in space and time as its owner goes about their day.