Check out Drones Are Responding To 911 Calls In This California City.
I agree that the misuse of the technology is possible. Just as police cars, police stations, officers' guns, batons, handcuffs, stun guns and other tools of their trade have been misused. This does not make drones inherently evil. It is the policies, and persons who operate the drones, that make for safety and proper use.
This was the first use of a drone in the manner described for law enforcement purposes that I've read. Likely there are others positive uses for law enforcement — which is usually a prohibited activity for many law enforcement agencies employing drones. Does that make sense?
Really, it is a lack of trust in the law enforcement discipline that is at work.