@Wilso,
I am an atheist just like you, Wilso, but unlike you I am not a parrot. I have a brain that can think independently. And I can understand your posts - that's not the problem. The problem is that what they say is false.
If Atheism was only an absence of belief, you'd be less dogmatic and more open to other people's ideas than you actually are...
Massive crimes were committed by some atheists during the 20th century. Some of these crimes can legitimately be linked to atheism, either directly when these leaders implemented a tenet of their atheist philosophy (e.g. destroy religion), or more indirectly when their atheist philosophy helped justify their crimes.
It's very simple if you think of it: why is it you don't kill people around you (assuming you don't)? That beggar that you see at 1:00 am in a dark allay, why not end his misery? Nobody will see you, nobody will care... Why not, if you fear neither God nor the police?
The only reason why not, is because you believe it is morally bad to kill other people. (hopefully)
Atheism is not necessarily criminal, but if a society becomes predominantly atheist and gets rid of the fear of hell and of religious morals, it may need to replace old moral codes by something else. No society can live and prosper without some sort of common ethic.
I understand that most of you live in societies that are still deeply religious and with a vast majority of Christians, so it may seem as a lunacy for you to speak an atheist society. I live in a society that is largely atheist or at least secular, and the issue of forging a set of values that will work for all, including Muslims and Muslim "unconverts" (I mean the youth of Muslim origin who do not believe anymore), is an important one here. And I am pretty sure it will become important in your societies as well in a few decades.