the.com/vigilante

means A person who takes it upon themselves to prevent or punish crime without legal authority to do so.

from Straight from Spanish "vigilante," meaning "watchman" or "guard," itself from the Latin "vigilans/vigilare," to watch or stay awake — the same root behind "vigil" and "vigilant." The word entered English in the 1800s tied to American vigilance committees, groups of self-appointed enforcers on frontiers where formal law hadn't caught up. So the term has always carried its own contradiction built in: it names someone being watchful and lawful-sounding while acting entirely outside the law.