Doesn't matter, because it exists universally.

Even when it's not at the hands of the official state, if a society at large is ok with it, justice killings happen.

Laws are inelastic, while society is fickle and impatient. Many live on a standard of right vs. wrong instead of lawful vs. unlawful.

Whether it's the state or vigilantism, both are ugly and prone to mistakes.

They are also inevitable and we live in a neverending cyclical status quo of one or the other.