If people die from tasers it sounds more as a product fault so that they might need different ones with varying power (e.g weak one for the upset guy in his 50's, strong one for the steroid-pumped armed robber) or poor use (such as aiming for the upper chest or head rather than legs/arms/groin).

As for the kid with a knife, it's a tough call. I'd prefer to disarm someone who's wielding a blunt weapon any day of the week, slightest mess-up in a knife situation can be deadly.

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Merchant and pirate were for a long period one and the same person. Even today mercantile morality is really nothing but a refinement of piratical morality.