A hot potato: Vizio paid $2.2 million to settle charges that its smart TVs had quietly tracked what was playing on 11 million screens back in 2017. As part of that deal, the company had to start asking owners for permission first. A new study, however, suggests that telling a current Vizio TV "no" doesn't change much, at least as far as its network traffic goes.
For the study, researchers at Northeastern University tested 12 smart TVs from 10 manufacturers. Together, those sets run the eight operating systems behind roughly 95% of US smart TVs. Every viewing scenario – antenna, HDMI, streaming apps and more – ran 30 times with automatic content recognition (ACR) turned on. Each one then ran 30 more times after the researchers opted out through the TV's own settings.
Vizio's SmartCast platform came out looking the worst. After the researchers opted out, the Vizio TV kept sending just as much data as before to an Amazon Kinesis server the team linked to ACR. That happened in every single run, even while the set sat idle on its home screen.
By comparison, only four platforms – LG's webOS, Fire TV, VIDAA and Sony's Google TV – fully went quiet after opting out. But the Samsung set continued sending ACR-like traffic in all 30 tests of the company's own streaming service. Roku's opt-out, meanwhile, doesn't cover The Roku Channel at all.
Still, the Vizio and Samsung traffic is encrypted, so the researchers couldn't see what was actually inside it. That's why they stop short of saying Vizio broke its FTC settlement. They only tested one Vizio set, too, so other models may behave differently.
Even a working opt-out wouldn't help on Vizio's free WatchFree+ service, though. It drops the name of each show or channel into unencrypted DNS lookups sent to stream delivery firm Amagi. That lets an internet provider, or anyone else on the network path, piece together a running list of what someone watched. And there's no setting to turn it off.
Walmart, for its part, bought Vizio for $2.3 billion in late 2024, partly to feed its growing ad business. Since March, select new Vizio TVs even need a Walmart account to unlock their smart features.
For owners who'd rather not be watched, the researchers suggest cutting the TV's internet connection and using a separate streaming device that doesn't run ACR. They've also published a blocklist of known ACR servers. In their lab tests, blocking the ACR servers didn't break anything, though the blocklist doesn't stop the WatchFree+ leak.