Never in history was an idea quelled forcefully, and those people are driven by an idea, you fight an idea with an opposing idea, a more attractive idea. And for this particular idea it is best fought with opening of minds. Throwing Bombs at them will only propagate the idea like an echo, over and over and over and over again.
People do not understand the idea that is driving them, none of you really does, and once you do understand it you will find why it makes so much sense, at least to them. And once you understand only then can you fight it. Ideas spread like a virus, from one person to another and to another, and it is this very idea which is the danger, the person carrying the idea, is a harmless, innocent, and quite honestly an intelligent person.
Imagine it this way, there is this virus that creates Zombies, these zombies when infected will go after every human being alive, some humans are more susceptible to this virus than others, never in any fiction was the Zombie apocalypse reversed by killing each and every single zombie, because that is impossible, it always has and will always be with a "cure". Now to develop this cure you must understand the disease. And if you never do find a cure, you will be eaten by zombies eventually.