Friday, February 24, 2017

Ultrasonic Spying

We're all aware of the many tracking tools used to assist advertisers in their pursuit of analytics. Aware enough that many of us use ad blocking software or choose to use services such as Tor in some circumstances. Another tracking method involves the use of ultrasonic signals that do not degrade our viewing or listening experience, yet is able to inform listening microphones on other devices of our activities. This, for example, could let an advertiser know you were present while a particular commercial played on TV. See the below snippet for a fuller explanation. 

"The technology, called ultrasonic cross-device tracking, embeds high-frequency tones that are inaudible to humans in advertisements, web pages, and even physical locations like retail stores. These ultrasound “beacons” emit their audio sequences with speakers, and almost any device microphone—like those accessed by an app on a smartphone or tablet—can detect the signal and start to put together a picture of what ads you’ve seen, what sites you’ve perused, and even where you’ve been.

SilverPush, a company mentioned in the above article, offers such beacons. However, in 2016 the FTC warned app makers using SilverPush code they had not properly given warning to their users that their microphones could be used in the background to listen to their activities.

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