One other thing, those that criticise the use of an increasing number of surveillance devices have a point. Remember we still hope to police by consent, so if the public regard the proliferation of surveillance devices as a step too far then the police should take heed.
May I just add something to this statement. I do not personally believe that the average policeman with a UAV is out to get me in any shape or form. I think that a major reason that any officer would be looking at something he shouldn't would be boredom*, and not any kind of corruption or malice.
The concern I often hear expressed about increased surveillance is generally targeted at the government, and a fear of what they want the info for...Not the police who gather it. Just my two penneth worth
*I am not going to tar any professional officer, but if it were me, I fear that on a hot summers day, the female sunbathers in the local park could become of interest
(yes it may be sexist and old fashioned, but at least it's honest)