Well-Intentioned Extremist: Plenty of them. The Empire’s (and Rim Free Zone’s – not that they’re really coherent enough to spend much time dealing with them, unlike the Empire, which understands that they’re both staggeringly counterproductive and vaulting merrily across the Moral Event Horizon) principal embarrassment in this department are the dark side of the Sanguinary Enforcers of the Liberty Ethic (see: Fictional Political Party), the mostly-Renegade Blood of Tyrants, who take the view that literally any violent action is justified if the people you take it against represent a non-consensual government, or advocate a non-consensual government, or tolerate a non-consensual government, or are standing a bit too close to… well, you get the picture.
Other examples elsewhere in the Worlds that at least someone can evidently appreciate if they just hear the friendly version of their aims – and not the details or the methods – include the Enforcers of Mortality (who object to immortagens for a variety of reasons, from the philosophical to the purely self-interested), the biochauvinists of the Biotist Alliance and their slightly more justified digital-supremacist counterparts in the Electron Reign, the deep ecologists of the Ecoprimacy System, Parents for Natural Children and other less-friendly-sounding genetic purists, and the assortment of baseline-über-alles groups united under the Never Last umbrella. And, of course, any number of species supremacists and other more classical whackos.
Lunacy. Lunacy never changes.