Sure. He told me a story about a SWAT team that got shredded by cartel thugs. The cartel saw them coming. Now they don't even take their cells with them and they keep their phones in Faraday bags as often as they can.

Unrelated, but this is similar to when the Navy had to ban sailors from wearing their Fitbit watches when they were deployed. It's kind of easy to find an aircraft carrier when it has has a few hundred Fitbits sending their location from the middle of the Atlantic.