Legislation saying that "network off" settings need to be respected and the device needs to work as much as a possible without a network connection, on pain of 2x revenue + penalty from whatever agreements you made selling data would go a long way.
No more cars that spy on you as you drive around when you turn of network services, no more TVs that spy on what you watch and so on.
What you sounds quite reasonable...from a consumer perspective. Laws are not written for consumers. You have no power and no voice and the vast majority of people are so completely checked out of reality that you are hopelessly outnumbered. Oh, and big business and government surveillance are both lined up on the other side. We are losing this one.
No more cars that spy on you as you drive around when you turn of network services, no more TVs that spy on what you watch and so on.