history coincided with the replacement of 2pp by 3pp. Modern governments, when they can assert their authority, usually forbid 2pp, calling it “taking
justice into your own hands” or “vigilante
justice” (which can also include 3pp but may also be 2pp by an offended group). The norms of 2pp tend to be based on retribution, although of course this is correlated with (at least specific) deterrence, so that both rationales can be used at once, whichever is primary. (“I’ll teach that SOB not to mess with me anymore. And, anyway,...