Seriously? Well not connecting them to the internet works less and less, Amazon is rolling out their 900Mhz mesh with echo devices and there's LTE-M, NB-IoT and such.
The idea of not letting a device connect to the Internet is slowly becoming a thing of the past unless you live in a faraday cage (which is becoming more and more tempting). Oh, correction, thanks to mesh networks like that of Alexa living in a Faraday cage is not actually enough if at least one device is connected. Yay.
I do just fine not connecting proprietary IoT shit to the internet. Sometimes I have to bust out a soldering iron, but if it is hardware you own it is always a choice.
Even with a mesh, devices still have to be authorised to get access.
Just don't do that.
The more difficult option is if they come with cellular modems built-in, thus bypassing any of your infrastructure (which needs authorisation). That of course is technically possible, tho probably commercially unacceptable (modems cost ~15 to 20 dollars in bulk which is significant at smart-tv scales, not counting the data cost).
More expensive IoT items like modern cars ship with factory activated cellular modem based tracking. Your options today are to buy older base model vehicles or learn to use a screwdriver and a soldering iron.
> Even with a mesh, devices still have to be authorised to get access. Just don't do that.
Nope, the whole point of Amazon Sidewalk is that it "just works." I don't think there's even a way to know what devices are connected, let alone any kind of authorization.
The idea of not letting a device connect to the Internet is slowly becoming a thing of the past unless you live in a faraday cage (which is becoming more and more tempting). Oh, correction, thanks to mesh networks like that of Alexa living in a Faraday cage is not actually enough if at least one device is connected. Yay.