“If they have smart phones, they can be tracked to within 10 feet ...”
Hadn’t thought of that. The question then becomes is anyone tracking them, and how expensive is the tracking operation if there is one.
All you need is the number and meta data about that number is available without a subpoena. Think 2000 mules. In that movie, the process was reversed — they had people with phones in a location, and they could track #s by location.
So ... if ya got numbers, you can track location EVEN WITHOUT LOCATION SERVICES TURNED ON. All carriers can track tower to tower with various degrees of precision. It’s in the network data.
If you get a subpoena, a treasure trove is available legally.