Not a literal statement obviously, but you could pick as examples any small country or region where locals took it upon themselves to form a self contained entity of any sort (read “feudal kingdom” “middle east dictatorship” “any communist country ever…” and the list goes on).
If the unit is small enough, and the people inspired/community minded enough, you can probably have a pretty fair and genuinely pro-populace oriented self policing unit. Sooner or later corruption and power mongering sets in though, and you’re back to the same problem.
The issue is likely not redistributing who has the power to police (as any group is likely to eventually fall into the same corrupt patterns), but how to change the system to minimize the ability for people to succumb to the usual human failings.
