The researchers have discovered that automatic content recognition (ACR) tracking is active most of the time, even when TVs are used as “dumb” HDMI devices. In other words, the TV manufacturers are monitoring your private moments as well. There’s apparently no monitoring of streaming content in the UK, but there is in the US.
The only good news is that these TVs can seemingly be configured to disable ACR, provided the owners know this activity is taking place and are able to find the right settings. (I recently looked at the configuration of our TVs again, and understanding the various settings was far from easy.)
Unfortunately, that’s no guarantee. I believe some devices have been found to scan for any open WiFi and join silently so they can phone home.