The ones I have read about were involved in the Johnson County War (in Wyo.).
That was in the 1890s. The War of the Regulation in NC happened just prior to the Revolutionary War. It was the warmup act, so to speak.
They were backwoods frontier rabble-rousers here, more on the side of forcing corrupt royal officials to obey the law themselves rather than being purely outlaw, though. Breaking into courthouses and dragging crooked officials out by the heels to be horsewhipped, tarring and feathering, threatening the royal governor to the point that he got on a ship and fled, that sort of thing. Not a whole lot different from what other groups using the same name did further west with frontier justice, I guess, but they were trying to “regulate” the administration of law and justice in colonial NC rather than intentionally be beyond it, to make it more regular and fair in the old archaic sense of “regulate.” NC royal government was really quite corrupt.