Ultrasonic Boom

Wired: Hundreds of Apps Can Listen for Marketing ‘Beacons’ You Can’t Hear.

“Beacon technology is also showing up in more physical locations. While the researchers didn’t find any ultrasonic tones being broadcast out on a sampling of television programming from seven countries, they did find that four of the 35 retail stores they visited around Germany did have beacons installed. “It was really interesting to find beacons at the entrance of some stores in two German cities,“ says Erwin Quiring, a privacy and Android security researcher who worked on the study. “It affects all of us if there’s some kind of privacy invasive technique we don’t know about and which runs silently on phones.“ “

(My emphasis.)

Link via dangerousmeta!