In the very long-run there's going to be a problem that if the trends keep continuing it will be possible for single crazy people to do nearly indefinite levels of damage. That's a problem whether the individuals are motivated by religion, ideology, or are just wacko. Charlie Stross in one set of novels imagined a world where there's a real problem that every crazy person can build their own nuclear weapon, but I don't think he took it to its logical conclusion. The solution here may be simply to spread out so much to other planets that isolated incidents cannot do enough damage.