This morning, I discovered this person's web site, which highlights his crusade against... well, humanity. He appears to be calling for nothing less than the obliteration of all forms of civilization, denouncing the harm Man has inflicted on the environment.
Now, without civilization, I think it's safe to say that a good 90% of us or more would be dead very quickly. Personally, my own continuing existence depends on modern medical technology -- I would be lucky to survive a week without modern medicine.
So, in essence, this guy is calling for wholesale genocide through applied Darwinism. He wants to reshape the world to suit his ideals, and if in the process literally billions of people die, that's just fine with him.
My moral question is this: at what point (morally, not legally) would I be justified in taking action to stop him? When would it be acceptable to thwart his plans, which would end up killing me and countless others?
(Disclaimer: I have never heard of this guy before, have no idea who he is or where he is located, and even if I did, I'm probably the least likely to actually do a damned thing. But while reading his manifesto, I could not help but personalize it and realize that the only role for me in his utopia is as mulch.)