Marketers use ultrasonic beacons — sound waves humans can’t hear — to send “encoded data” to smart devices within earshot. For example, an ad on TV can transmit an ultrasonic beacon that your phone picks up. Ultrasonic cross-tracking allows marketers to create user profiles, monitor user behavior, track users’ locations, and deliver targeted ads. “You pick up the phone, go on social media, and see the same ad you’ve just seen on TV. Coincidence? No, just highly advanced and elaborate marketing,” NordVPN said in a blog post. This survey, conducted between Feb. 23 and Mar. 7, involved over 10,000 adults from 11 countries.
Ultrasonic Cross-Device Tracking
Adult humans cannot usually hear high-pitched frequencies above the 18 kilohertz (kHz) range, but “they can be detected by various smart devices (like your phone or laptop),” NordVPN explained. While marketers have been using ultrasonic cross-device tracking for some years, this survey shed light on how “widespread” it has become and users’ attitudes towards this invasive tracking. About 53 percent of the American respondents in the survey said they had seen ads on their devices for something they had recently discussed or seen on TV. Nearly 40 percent of these people said it made them feel “followed.” In the UK, 45 percent of respondents said they had experienced this, and 49 percent said it made them feel “followed.” While about 13 percent of the UK respondents said this made them feel “scared,” about 20 percent of the American respondents said it made them “happy,” and, disturbingly, 12 percent said it made them feel “special/important.” Most of the respondents said targeted ads were most evident on their smartphones. However, about half of the U.S. and Canadian respondents also noticed it on their computers. The figure was much lower at 33 percent for UK respondents. While some people accept this type of invasive tracking as part of the online experience, others are calling for more privacy controls. “If you’re talking about hamburgers, finding an advert for a nearby fast food restaurant could be a refreshing surprise or deliver a sense of unease. The important thing is that consumers feel in control, rather than a product themselves,” Adrianus, a cybersecurity advisor at NordVPN, explained. A 2022 study by the University of Pennsylvania revealed that most Americans accept marketers using their data as inevitable. Meanwhile, a survey published in January revealed that most Canadians are concerned about their online privacy and want more control over their data. According to NordVPN’s survey, most people don’t know they can change their phone’s permissions and limit tracking. About 50 percent of Americans said they didn’t know they could restrict the microphone permissions on their phones to prevent their devices from listening. More than 60 percent of the respondents were unaware of this in Australia, Canada, and the UK. “We need to be concerned about everything interfering with our privacy, especially — without our consent and awareness,” NordVPN said in an email. “For now, it’s tricky to say how often smartphones are eavesdropping on your private conversations — but the technology is certainly in place to do it.”
Tips to Limit Cross-Device Tracking
User tracking and profiling have become increasingly rampant thanks to the voracious appetite of big data and marketers for user data. Last month, researchers revealed that consent boxes are ineffective as websites record keystrokes and collect user data even when users don’t submit this data. “When it comes to our smartphones the line between support and surveillance can sometimes seem paper thin. Smart speakers, for example, rely on being able to hear our commands — via microphones — to help with requests, yet there are times we notice them switch on, seemingly unprompted,” Adrianus said. To limit cross-device tracking, NordVPN recommends reviewing your app permissions and restricting access for certain apps. You can stop ultrasonic cross-device tracking by blocking certain apps (like social media and browsers) from accessing your microphone when you’re not using them. You’ll find your app permissions under Settings > Permissions. While you’re at it, also block these apps from accessing your camera. NordVPN further recommends using a VPN and reading through apps’ privacy policies carefully, with an eye out for any mentions of “inaudible sound.”
