Earlier quoted context omitted.
The article is about sneaking phones (and chargers) into prisons How practical would it be to erect a Faraday cage around a prison? How practical would it be to jam the signals? I bet one could interdict a lot of criminal activity by stopping or eavesdropping on prison cell phone conversations.
Stingray?
Are you suggesting a legal and lawful use for the Stingray that the mass population would agree to? Ha, get out, that's not what the Stingray is for! :)