Dumb phones won't solve the problem really. Any phone has to connect with a tower. Phones almost always connect to multiple towers simultaneously. Triangulation is the trivial matter of correlating signal levels from the log produced by a couple of those towers. That's assuming you're worried about your carrier (or any other, since your phone will talk to other towers) or a government body accessing your location. Acquiring location data directly from a smartphone log makes less legwork and probably fewer court orders.. hence why law enforcement is always interested in that stuff. Personally I don't worry about any of that. I do worry about businesses (google, apple, Samsung, etc etc) having the data because typically businesses like that suck at security. Find one that doesn't have a press release about customer data being exposed in the past few years.