Your Phone Is Listening—Literally Listening—to Your TV
Quote:/...a newer method of cross-device tracking wanders into the realm of science fiction. According to a filing from the Center from Democracy and Technology, a digital human rights and privacy advocacy organization, companies have figured out how to use inaudible sounds to establish links between devices.
Here’s how software from SilverPush, a leading provider of “audio beacons,” works: When you visit a website that uses SilverPush tracking technology, the site causes your device to emit an inaudible ultrasonic sound. If any other devices you’ve got lying around—a laptop, a phone, a tablet—has an app installed that includes SilverPush code, it’s listening for that sound. If it hears it, SilverPush knows that the two devices are close to one another and, presumably, belong to the same person.
More recently, SilverPush expanded into television advertising: Certain TV commercials include an ultrasonic audio beacon. Any nearby devices running SilverPush software will be listening for the beacon—if a device hears it, it records the match, allowing the company to figure out what ads users watch and for how long, and add that information to the user’s profile.