If the government wants to track your phone, they can do so under any condition unless your phone is in a faraday bag. This is at least what I have come to understand. If someone knows better, please correct me #asknostr
Discussion
I would assume if it's in a faraday bag there's still a lot of tracking it can do internally while waiting for an opening
But a faraday bag cuts off all radio communication right? So no phone signal, Bluetooth, WiFi or GPS. Any audio and video would be incomprehesibly muffled by the bag. And the phone isn't being actively used while in the bag. So what info is left to send at that point?
Audio might be better than you think, maybe good enough to analyze later in the data center, along with accelerometer and gyro and maybe barometer data etc, to try to get some location guesses, or at least an estimated maximum possible distance traveled.
Researchers have shown a laptop microphone can tell what a user is typing on the keyboard (without access to the keyboard input) - never underestimate what a few scraps of data can do