I don't particularly object to professional pilots representing lawful authority enforcing the law through aerial surveillance. I do object to amateur pilots representing extremist groups enforcing their own personal agendas through vigilanteism and using aircraft to harass other citizens.
I am surprised it took so long to get round to this point, but I think it is the most interesting. I agree entirely, and I am surprised that they allow it today. If this sort of thing isn't stopped quickly you will have situations like pro-lifers hovering over abortion clinics, then pro-choicers monitoring them -- a recipe for mid air collisions. Today it is a small number, probably because people with licenses prefer to pass their time doing other things, but if political groups see that it works they will start sending their people to get flying lessons.