I loosely follow the NAP. But there are some people who should just be taken out of the picture.
Some stuff doesn't effect you immediately, or you might not hear about it 'til later. Maybe it doesn't effect you much, but their actions effect other people who are close to you - and in "the real world", what are they supposed to do? Call the cops and get no results? Cops don't respond to threats that can't be proven, and general low-level harassment.
How many times are you supposed to forgive and forget, or turn a blind eye?
This stuff builds up over a period of time and effects the general quality of life.
I don't have a problem with "those people" getting roughed up, threatened, or fucked with via "dirty tricks" until they are so buried in problems, they have compounding disasters making them leave town, or hunker down in their house, having learned their lesson to leave people alone.