Little Falls Police Department PINGS a phone in order to locate he suspect.

Take a look.  This is interesting.   So if you ever want to not be found you have to TAKE THE BATTERY OUT OF YOUR PHONE.   This is true, also, if you don't want your conversations surveilled.    Take the battery out, before talking with any friends and have them take their battery out too.   Even when your phone is shut off, it can be used to monitor and surveil what is going on in the room where your phone is located.