VIZIO 85 in Mini LED Quantum 4K QLED HDR Smart TV
Image credit: Vizio
Your smart TV can take snapshots of whatever is on screen and send them to a company that identifies what you’re watching. The technology is called automatic content recognition, or ACR, and the viewing information it gathers can be shared with or sold to other companies to target ads or measure viewing habits . Most smart TVs let you opt out in the settings, which is supposed to stop collection and transmission of the data, but a Northeastern University study found that opt-out didn’t work on Vizio TVs.
The researchers tested 12 smart TVs from major brands, including Vizio, which Walmart purchased for roughly $2.3 billion in December 2024. They checked what each TV sent over the internet with ACR tracking turned on, then again after opting out in the TV’s settings.
Opting out fully worked on LG, Sony, Amazon Fire, and Supersonic TVs, and Samsung’s setting partly worked. On Vizio, switching off tracking changed nothing that researchers could measure: every time they opted out, the TV kept sending the same data to the server that handles its tracking.
The data is encrypted, so the researchers can’t see what is being transmitted or how Vizio used it. They also tested only one Vizio TV, so other models may behave differently.
Vizio’s free proprietary WatchFree+ streaming service has a separate problem. It exposes the title of each show or channel you watch in an unencrypted process that your internet provider, or anyone else on your network’s path, could read. The researchers say no setting turns that off.
Because opt-outs fully worked only on other brands, the researchers suggest Vizio owners who want greater viewing privacy disconnect the TV from the internet, which keeps it from reaching the tracking servers at all. You can still watch through an external streaming device that doesn’t run ACR.
They tested TVs rather than plug-in devices such as Amazon’s Fire TV or Roku, so this study can’t say whether those devices track you. However, on the Roku and Fire TV sets they did test, the researchers saw no tracking-style data tied to Netflix, YouTube, or Tubi with ACR turned on. Roku’s own streaming service was tracked, and Roku’s opt-out won't prevent it, so check the privacy settings on whichever device you pick.
