Bluetooth Low Energy (BLE) beacons are actually nothing new. Since 2013 this standard has been used in many electronic devices. With the advent of contact tracing apps, the technology has attracted a lot of attention lately.
BLE beacons are like small lighthouses which can send signals to nearby devices such as smartphones. Beacons do not receive signals and do not collect data. These tasks are done by apps, e.g. free weather apps or apps from retailers that you have installed on your smartphone. When an app detects such a signal, it sends information back to the server of the company that placed the BLE beacon. In combination with other data about you, advertisers are then able to create a profile about who and where you are and what you are buying. This allows companies to display you ads for products that are tailored to your interests. We call this practice “retargeting”. This article in the New York Times describes in more detail how BLE beacons work and how they are actually used.
Unlike other location services such as GPS or cell towers, BLE beacons offer an extremely precise location determination. Due to their low energy consumption and reliable indoor performance, they are particularly popular in the world of the Internet of Things.
So by going to stores, cinemas, event centers, hotels and by using public transport, you move in an invisible beacosystem and reveal a lot of information about yourself – mostly without your knowledge and consent. Beacons can also be used to determine your location precisely without the use of GPS. To find out which apps do this, check your privacy settings under “Location Services”. It is worth restricting the sharing to apps where it is obviously necessary.
Tech giants like Google and Apple are also heavily involved in this game. In addition to using their own beacon monitoring via iOS and Android, they have for years allowed companies to equip the apps offered in their app stores with certain monitoring functions based on Bluetooth.