The link has a ton of information.
Now, It is obvious that putting it completely offline is more safe. But, some people often use the TV’s to watch Netflix or something like that. Then they might forget that it is still connected to the internet when they are done watching.
Under Privacy Settings, there are options for Device Usage Data, Collect App and Over-the-Air Usage, and Interest-Based Ads. All are enabled by default, but you can disable them.


There was some sort of scandal a few years back that some smart TVs (Samsung?) were using not just open networks (let’s be honest, there usually aren’t any), but other smart TVs if the same manufacturer to be able to send their telemetry. I don’t know what game of that, or if that was ever made illegal (probably not).
Source? Keep hearing people say this but no one ever provides a source. Think its just a tail at this point.