I want to make clear that I am not referring to individuals, but a philosophy and its affect on people in general. It's quite true that atheists can be anything and everything, however their philosophy, I believe, is harmful. And, it's not just atheist philosophy, it includes the philosophy of agnosticism.
The problem is that this is a social issue debate, and there aren't going to be any linear relationships that are going to be easily noticed. It comes from holding a particular perspective and seeing how that perspective explains human behavior as a whole and what we see happening in the world (as a whole).
I have a strong intuitive feeling that most crimes and self-inflicted harm occurs in homes where spiritual meaning was not instilled in the children of those homes. As these young adults grow up, they experience intense upsets that under a mentality where spiritual meaning is at a high, these intense upsets are dealt with in a manner that is mostly socially acceptable. However, there are many, many instances where people who lack this spiritual center are unable to attach enough meaning to things like sports, education, material success, etc, and therefore they seek out more extreme measures to obtain that meaningful experience (to fill the vacuum in their lives). These extreme measures are often innocuous, but as secular society ages, the former innocuousness is no longer satisfactory, and even more extreme measures must be taken in order to obtain the same meaningful 'fix'. This, I believe, best explains some disturbing trends that we see in society today.
I recently watched portions of a Donuhue show where a town meeting was held to discuss Columbine and how Americans seek resolutions often through violence. That might be, however what I didn't see addressed by that secular show was the impact of secularism on society. Secular societies think that by taking guns away, that somehow we will solve these problems. That might help in the shortterm, but in the longterm it won't resolve these issues because it doesn't address the needs that those two evil kids had in their minds. They were trying to fill that vacuum of meaning in their lives. When the one shot that Christian girl the question they asked was "Do you believe in God?", she said "yes", and they said "why?" and shot and killed her! I don't mean to say that this is what happens when you become an atheist, but what it does show, I think, is a disturbing effect of secularism. It's not a single case. Unless secularists understand their impact, as a whole, upon society, we are going to see more and more of some very disturbing behavior.
Now, I realize that religion also has its problems - perhaps even worse effects than this secularist trend. We experience the best of all worlds, I think, by being neither fundamentalist or secularist. The answer is to hold a spiritual meaningful life that avoids fundamentalist or atheistic trends. Unfortunately, as the effects of secularism build, it gives fuel to fundamentalist movements. To avoid such possible outcomes, it is better for spiritual meaning to be promoted in society and move away from the hollow meaning of life that atheism/agnosticism promote. That promotion only encourages fundamentalists and the crazy 'science' that they represent.
Warm regards, Harv