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.
I am a bit puzzled about the “even when your laptop is connected” part.
I have a small android box connected to it and am not using apps on the TV so it should have no chance of sending screenshot out even if it takes them.
The TV itself is not connected
what kind of Android box do you have? anything you recommend? (looking to have some sort of streaming client)
Nvidia Shield. The bigger one.
Yes, it’s a couple of years old at this point, but it’s still the best device of its kind.
Not to mention the remote is FANTASTIC.
the google tv with chromecast dongle is quite decent, good price/performance ratio
It’s a Chinese one that I used at first for retro gaming with emuelec. Now it is dual boot and I have kodi and newpipe on it too.
Sorry for being paranoid but can the TV piggyback the connection used by the the streaming device/android box to send data back to the TV OEM?
Not yet but it is clear in the future most devices will be able to do that, we will have ubiquitous low grade internet access everywhere. Your neighbours devices will let your electronics snitch on you even if you seal up your own internet
Good point. We can have a honeypot wifi. Check my other comment in the thread.
Okay, so for the new folks with networking, how do you set up a honeypot wifi? Have a (second) router powered on with no connection? Or is it something you can set up with one router?
Many routers have a functionality to create a guest wifi. These usually run on a separate VLAN so that it can’t access other devices on the network. After creating this guest wifi, you have manually disable internet access on this but keep the wifi on.
Unfortunately the process varies between router to router.
The only connection the TV has is hdmi. I do not think that back and forth communication is possible there.
If the TV has wifi, it can do its thing but that would also be easy to disable.
I think for the TVs internal wifi, it’s better to create a honeypot Wi-Fi exclusively for it, or a VLAN. It will constantly try to send data and fail. If we don’t let it connect to anything, the TV might start sniffing for other open networks.
But if you connect your phone to the android box then the TV could use the phone to send the screenshots.
TV->android box->phone->internet.