A substantial group of people have rejected "smart" phones.

Alas, even a non-"smart" phone tracks the user's location — with the phone company and Big Brother, though not directly with other companies — and can be remotely converted into a listening device. That's why I refuse to carry any kind of portable phone.

If you own a car, watch out: it may contain a built-in cellular modem that makes it the equivalent of a "smart" phone. Nowadays it may even have a microphone to listen to conversations in the car. But you can probably disconnect it. Wrapping it in aluminum foil may be enough to make it cease to communicate.