At least in my house, all Internet traffic still has to go through my router. Could that be the place where we control who and what our things talk to?
That would require reverse engineering the application running on the cloud server and the transfer protocol so that you can host an equivalent version yourself. It can be done, see for example pirated Battle.net servers for the Warcraft games, but in many cases the effort simply is too much.
Aha. Perhaps I'd be satisfied with simply blocking the traffic, assuming my refrigerator is designed so my food won't get warm if the fridge can't phone home. (For now, a fridge with a mechanical thermostat and no microprocessor seems to keep my food cold).
