So what? I mean seriously if you are going to go underground and off the grid why in the hell would you have any electronic device at all like a cell phone, computer, iPad, GPS in your car whether factory or aftermarket?
This whole thing sounds like a bunch of paranoid backyard commandos looking to scare the shit out of even more people. Disconnect from all communications technology if you don't want anyone to know where you are...Besides if the infrastructure collapse you are all praying for happens all any of it will be is just another boat anchor weighing you down as you bugout to your fortresses in the hills.
There are two kinds of people, those that are prepared, and those that suffer.