[targonca]

What data? - you ask. Let's see:

- audio recordings (smart TVs have microphones)

- photos of your living room (smart TVs have cameras)

- still images of TV content

- SSIDs of neighbouring WiFi routers for geolocation

- data from scanning nearby smart devices Bluetooth

- daily/weekly usage data

- data from scanning USB devices plugged into the TV (e.g. list of filenames from your pendrive / USB HDD)

[tremendo]

Still, if TV isn't online, you don't give it access to your network, that doesn't go anywhere.