In general, a random stranger - or even someone I knew from school, folks working for the parks department, and so on have little or no power over me.

The police or other law enforcement, however? These are folks that not only can abuse the power, but use it to factually or falsely accuse me of a crime. That's enough to ruin a life. You don't even need to be convicted for it to cause serious life issues, sometimes for years. These are the very people that I should be able to turn to when someone abuses it, and I am under the impression they would cover up their own abuses ... much like they do now.

The same really goes for politicians, but the scenario is different.