From Google Play, hundreds of applications for Android have been removed, equipped with an ultrasound beacon that can spy on the user. This is reported by the Daily Mail.
At the heart of this technology is the exchange of ultrasonic signals between various devices that are not audible to the human ear. As a result, a smartphone on which an application that reads such signals is installed collects information about where the user is located and what he does. Marketers and advertisers can then use this data to create targeted advertising.
Researchers at the Braunschweig Technical University found that code for recognizing ultrasonic signals was introduced, including in mobile applications of major brands, for example McDonald's and Krispy Kreme.