By Jeremy Hsu on September 24, 2024
Popular smart TV models made by Samsung and LG can take multiple snapshots of what you are watching every second – even when they are being used as external displays for your laptop or video game console.
Smart TV manufacturers use these frequent screenshots, as well as audio recordings, in their automatic content recognition systems, which track viewing habits in order to target people with specific advertising. But researchers showed this tracking by some of the world’s most popular smart TV brands – Samsung TVs can take screenshots every 500 milliseconds and LG TVs every 10 milliseconds – can occur when people least expect it.
“When a user connects their laptop via HDMI just to browse stuff on their laptop on a bigger screen by using the TV as a ‘dumb’ display, they are unsuspecting of their activity being screenshotted,” says Yash Vekaria at the University of California, Davis. Samsung and LG did not respond to a request for comment.
Vekaria and his colleagues connected smart TVs from Samsung and LG to their own computer server. Their server, which was equipped with software for analysing network traffic, acted as a middleman to see what visual snapshots or audio data the TVs were uploading.
They found the smart TVs did not appear to upload any screenshots or audio data when streaming from Netflix or other third-party apps, mirroring YouTube content streamed on a separate phone or laptop or when sitting idle. But the smart TVs did upload snapshots when showing broadcasts from the TV antenna or content from an HDMI-connected device.
The researchers also discovered country-specific differences when users streamed the free ad-supported TV channel provided by Samsung or LG platforms. Such user activities were uploaded when the TV was operating in the US but not in the UK.
By recording user activity even when it’s coming from connected laptops, smart TVs might capture sensitive data, says Vekaria. For example, it might record if people are browsing for baby products or other personal items.
Customers can opt out of such tracking for Samsung and LG TVs. But the process requires customers to either enable or disable between six and 11 different options in the TV settings.
“This is the sort of privacy-intrusive technology that should require people to opt into sharing their data with clear language explaining exactly what they’re agreeing to, not baked into initial setup agreements that people tend to speed through,” says Thorin Klosowski at the Electronic Frontier Foundation, a digital privacy non-profit based in California.
Something doesn’t add up. How can a TV take 100 Screenshots of 4k content per second? No wifi has that bandwidth. No embedded processor has that capacity.
It doesn’t need a 4K screenshot. It needs enough data/metrics from any given single frame to run it through analytics and an algorithm to tailor ads. Backend surveillance like this isn’t interested in fidelity to the human viewing experience. It needs identifying data. That can be had through a combination of low quality data scrapes done numerous times.
“Screenshot” is more like a metaphor here. Sort of like how your Apple or Google photos are “private,” but the data and analytics taken from them you’ve given away. It’s like if you told me I could look at all the photos on your phone and take as many notes and subject them to as much analysis as I wanted, but I promised not to actually physically keep your phone/photos. Probably makes you feel like your photos are securely still in your possession, but I got what I wanted. Your data is technically private, but my data about your data is mine.
I’m the OP, but not the author of this article posted.
After I dove deep into the study, the study said it records data at 500ms. And then it batches the data together, and only sent data once per minute back to Samsung. Between 8kB and 9kB of data per minute. So definitely not 4K screenshots.
it doesn’t necessarily take full resolution images
just because it can capture images a few hundred milliseconds apart doesn’t mean it’s continuously capturing images. It could be several in short bursts with a delay between groups of images.
You know when people say “I’ve only talked about this once, never searched for it, and then I got ads a few days later”?
What if it hasn’t been phones that were listening (despite Siri/Google Assistant/Alexa mis-identifying something as a wake-word being the most sensible explanation), but TVs?
Why not both
It may be snapping multiple in a small period of time. Compressing them in the background then trickling them back out.
It doesn’t say the screenshot must be full resolution and it doesn’t say the screenshot is immediately uploaded. A couple seconds to downscale and compress would work the same as far as content identification is concerned
360p is probably enough. And that’s “up to” per second, average is probably far far far less.
Probably a data snapshot, not an actual screenshot.
I’m pretty familiar with how one particular brand of TV works, and you’re right, it’s absolutely not screenshots. It’s a handful of single pixels across the screen. By matching these pixels against known content it’s possible to identify what was being watched. Not too different than how Shazam can identify a song.
That’s not to say all TV manufacturers work that way.
Not mentioning taking 100 screenshots each second with what - 25 frames per second? - is kinda overkill…