Automatic content recognition (ACR) is built into most smart TVs. According to the researchers behind the study Watching the Watchers, 82 percent of U.S. households have a smart TV that can take snapshots of what is on screen and report them back. These snapshots, or fingerprints made from them, are matched against a library of known content.
The team tested 12 TVs from ten manufacturers, covering eight operating systems with about 95 percent of the U.S. market. They ran ten viewing scenarios in 5,943 automated experiments, with ACR both opted in and opted out.
Every operating system they could analyze tracked antenna broadcasts, while no TV tracked Netflix or YouTube. Vizio’s SmartCast OS even sent ACR-pattern traffic while idle on the home screen, in every run.
Opting out fully worked on only four operating systems: webOS, Google TV on Sony, VIDAA OS and Fire TV OS. On Vizio, the opt-out had no observable effect. On Samsung’s built-in streaming service, all 30 opted-out runs still showed traffic consistent with ACR. Roku’s opt-out does not apply to its own streaming service.
Most ACR traffic is encrypted, so the researchers cannot confirm what the data contains. Check what the opt-out on your TV actually covers, and treat your viewing habits as personal data.
