To say "Christians would never do that" is really ignorance, I would never say that. Christians have to be self-critical. In the many discussions e.g. on TV I've watched about Islamism etc., it has always been said that Christians were cruel too, I don't see this is denied by the Christian churches in my country, definitely not by the Protestant Church, which is generally very self-critical.

There are extremists who kill people in all religions, and there are also extremists in ideologies outside of religions.
Of course no one kills in the name of atheism, because the term atheism expresses something which does NOT exist (a god), but often an ideology takes its place and makes somebody kill, like Mao's idea of communism - so where did atheism help?

All I'm saying is that wiping out religion wouldn't wipe out crazy people who kill for the sake of extreme ideas. Killing in the name of Christianity is of course so absurd in view of the Commandment not to kill and Jesus' message, but if an individual constructs weird ideas, be it developed from a religion or an ideology, it's hard to stop madness.