Turning off tracking on a smart TV may not stop it from communicating with tracking-related servers.
Researchers at Northeastern University tested 12 smart TVs from 10 manufacturers and found that some continued sending network traffic associated with automatic content recognition (ACR) even after users opted out. ACR is technology that can identify what people watch on their television screens.
The findings raise questions about how reliably smart TV privacy settings work. However, because much of the traffic was encrypted, researchers could not conclusively determine what information was transmitted or whether viewing histories continued to be collected.
What the tests uncovered
Opt-out buttons exist to give users control over whether their smart TVs collect and transmit viewing-related data.
However, after running 5,943 experiments, researchers found that some TVs continued sending network traffic consistent with tracking even after users had opted out, raising questions about whether these privacy controls work as expected.
At the center of the findings is automatic content recognition (ACR), a tracking technology that allows a smart TV to identify what's playing on its screen.
Because ACR can be implemented at the operating system (OS) level, it can potentially recognize content beyond the TV's built-in streaming apps. This means that disabling tracking may not always stop the network activity associated with ACR.
Results varied by platform. Researchers observed continued ACR-related network activity in several scenarios involving Samsung TVs and across the tested opt-out scenarios involving Vizio devices. On Roku OS, the opt-out did not extend to The Roku Channel, the platform's built-in streaming service.
By contrast, the tested LG webOS, Sony Google TV, Amazon Fire TV and VIDAA systems suppressed the identified ACR-related traffic after users opted out.
The findings do not establish that manufacturers continued collecting or using viewing histories after users opted out. Much of the observed traffic was encrypted, preventing researchers from confirming its contents or determining how any transmitted data was handled.
Instead, the results highlight differences in how the tested platforms implemented privacy controls and handled ACR-related network activity.
A hidden cost of watching TV
The disparity matters because consumers have little reason to expect their privacy to depend on which TV operating system they buy.
People may pay for a television and streaming subscriptions without realizing their viewing habits could also become another revenue source through data profiling and advertising.
Viewing habits can reveal personal interests and routines, including through content played on devices connected to a television. When combined with information from other devices or online accounts, those records could contribute to more detailed advertising profiles and reveal information users did not knowingly choose to share.
The wider concern is how much faith users can place in online privacy controls.
Tracking can involve multiple technologies operating at different levels of a device or service, so opting out of one method may not cover the others. This leaves consumers with limited visibility into how their data is collected and combined, even when they believe they have taken steps to protect their privacy.
What you can do
Start by checking your TV's privacy settings and disabling ACR and any available viewing-data or personalized advertising options. However, the study found that these controls did not consistently stop ACR-related traffic on every tested system, meaning users cannot always rely on the settings alone.
If you're shopping for a new TV, review the manufacturer's privacy policy and look for clear controls over automatic content recognition, viewing-data collection and personalized advertising. Independent privacy testing can also help, although results from one model or software version may not apply to an entire brand.
Manufacturers control the TV's operating system and software, including how data collection works behind the scenes, so users have limited ways to verify whether every tracking mechanism has been turned off.
If you already own a connected TV, you can also block known ACR-related domains through your router or a network-level filtering tool, using the researchers' published endpoint list as a starting point.
Disconnecting the TV from the internet offers stronger protection against its internet-based tracking, although it also turns off online features. External streaming devices may provide another option, but they have their own privacy practices to consider.
No smart TV setting can guarantee complete privacy. Users can reduce unnecessary data sharing by reviewing tracking controls, limiting internet connectivity and checking independent privacy research. But the study highlights a larger problem: consumers often have little visibility into whether the privacy choices they make are working as intended.
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