This assumes a certain (low) level of malicious intent. A fully malicious TV will connect to open WiFi nearby or use even more exotic methods to exfiltrate data.

>A fully malicious TV will connect to open WiFi nearby

Connect to your own wifi and block any traffic?

If you've got logic to connect to nearby open Wi-Fi, why wouldn't you also use it as a fallback if the primary Wi-Fi is down?

Even if they don't do this yet it's only a matter of time before the manufacturers catch on and start doing so.

In that case, the only hope you have is play the cat and mouse game and hope they give up before you do. Realistically though, they probably won't bother escalate past this point because the people who would go to such lengths are a tiny minority, and going after them don't make business sense.

>If you've got logic to connect to nearby open Wi-Fi, why wouldn't you also use it as a fallback if the primary Wi-Fi is down?

One idea to counter this would be to use something like this[1] to deauth the TV instantly, or spam a bunch of open networks so it gets stuck trying to connect to those rather than actually working ones.

[1] https://github.com/spacehuhn/esp8266_deauther

The problem is that putting up with this doesn't actually send a message to the manufacturer that this is not OK, so they'll just keep doing this and perfecting their malware-like techniques until it's completely unblockable without some military-grade signal jamming equipment.

Even if it can be blocked, I don't recommend anyone buy these and look for alternatives (commercial displays, old second-hand ones, https://ironcast.tv, etc)

You're still assuming it won't detect this and periodically phone home from an open network.

It might be better to buy a dumb computer monitor

Yes, I know someone who did that, although for a different reason (to reduce lag).

They don't have those in 70" sadly.

Want to vouch for the projector route if you aren't a total definitionphile.

I have a $80 one off Amazon with 4000 4.5 star reviews. Gives about a 8'x6' pic on my bedroom wall. Has all the inputs.

Eighty dollars!

Getting a projector is a good option these days. They're cheap and can give you a home theater experience with easily twice that size. Just measured my setup and it ends up at ~130" diagonally.

There are limitations in the room you can use (not too bright, big white wall, good place to place the projector). But if you can manage it I strongly suggest it.