[arbitrary.squid]

On smart phones you can turn this feature off. phone companies can still provide a trail of what cell phone towers your phone has connected to, in the same way that using a credit card leaves a trail of where you've been.

[Secret Agent Man]

True. But if you keep your phone off, I don’t think there’s any mechanism that keeps cell towers tracking it. I wouldn’t think it’d be expending energy that way if it’s turned off.