[Carry_Okie]

So if you value privacy turn off the phone’s radios when not in use or maybe stick it in an enclosed wire mesh pouch,

The cell phone periodically checks with the closest tower. That means when you attenuate the signal the phone boosts it as if the tower was farther away. So when you shield it completely, what you are doing is burning up battery power MUCH faster and may induce early failure of the electronics.

[Trod Upon]

Not an issue with most modern phones. They can be put into “airplane mode” (all radios off) with one or two touches. The pouch is for the extra paranoid who might suspect the phone is really just in a listening mode, waiting for external signals to provide commands, when the radios are set “off.”