Without getting too specific, I can tell you certain law Enforcement agencies has exemptions to this and those requirements are not applicable in all cases. Several agencies in my area have purchased drones (Via Federal Grants) within this last year for Re-Con surveillance, re-creating crash scenes, criminal and investigative purposes, Thermal mapping, 3D Mapping integration kits, etc.
I can tell you firsthand, the agency I work for, purchased a $3000 drone and all that was required was the instructor to demonstrate a six hour course without any certifications provided and no test was needed. Even fire departments were exempt from any Knowledge tests or certifications. Civilians DO have to compete the necessary guidelines or at least they are instructed too.
Also, law enforcement agency's that incorporate the use of a drone within their department, MUST have a written department policy and procedure on this, which covers privacy extents. Which, must be followed and adhered to under practices, which overrides civilian requirements. Agency should NOT be using any drones until they have a policy/procedure in place. At least according to the training that I attended.