I suppose it depends on how you view things and what tradition you're from.
I have a very old-style view, where courts provide systems that substitute for private vengeance and thus become legitimate by being willing to hear complaints of harm, so from my point of view, if a court hear the matter, the affected person can take whatever measures they wish, which of course has important consequences in cases of legal immunity-- when my view is taken, legal immunity is something one desperately wants to avoid having, because whoever has it must contend with private vengeance.
And if people in their majority, in their stupidity or cleverness, reject your argument, isn't then vigilante action deeply anti-democratic?