Well, no, now that I think about it, it isn’t wifi either it’s the mobile phone signal that they use for traffic. So turning wifi off wouldn’t help. Airplane mode should probably do it but they probably have a way around that. Turning off the power is the only way I could say that you’d be safe, safer still if you took the battery out. Safest bet is to throw it out the window. :-|
Hubby and I have series discussions about ditching the smartphone. Neither of us care for how it monopolizes family time. And yet, I no longer have a computer able to be online so I only freep on my smart phone. It's a dilemma.