Or when challenged they drop the charges as to not disclose the true "source". https://arstechnica.com/tech-policy/2014/11/prosecutors-drop-key-evidence-at-tri

Or when challenged they drop the charges as to not disclose the true "source". https://arstechnica.com/tech-policy/2014/11/prosecutors-drop-key-evidence-at-trial-to-avoid-explaining-stingray-use/ https://arstechnica.com/tech-policy/2014/11/prosecutors-drop... https://arstechnica.com/tech-policy/2015/04/alleged-getaway-driver-challenges-stingray-use-robbery-case-dropped/ https://arstechnica.com/tech-policy/2015/04/alleged-getaway-...