“DO NOT MENTION ALPR USAGE TO THE OCCUPANTS OF THE VEHICLE. DO NOT MENTION ALPR USAGE IN YOUR REPORT OR COMPLAINT UNLESS ABSOLUTELY NECESSARY.”
That is a written policy, in all caps, telling officers to keep a surveillance system out of the paperwork. Leave it out of the report and it never reaches a defense attorney, a judge, or a records request. Federal marshals have driven files hundreds of miles to put them beyond the reach of a FOIA. The concealment is the design, not a side effect.