I can see the need for extremely small UAVs, but the entire non-military UAV concept runs into serious problems when you consider how cheaply you can purchase the services of a living, breathing, thinking pilot.

In short, most pilots will "fly for food" due to their emotional attachment to their profession. The also give you a level of flexibility that would be difficult to impossible to match in a UAV for any price.

There is also an "over-professionalization/militarization of police forces" issue here. While it would take more than a short post to an internet forum to explain fully, I believe that police forces in the US are becoming much too professional in nature and this professionalization damages the participatory nature of the democratic representative republic. UAVs are just one more step to excluding "civilians" from participation in law enforcement.