Of course, this doesn't factor in the numbers of murders carried out by atheist regimes such as those led by Mussolini, Castro, Mao, Lenin and Stalin, just to name a few.
Actually, Dawkins has trashed Islam.
See http://www.youtube.com/watch?v=K1b0QKO1rJQ where he takes on an Islamic cleric.
In this one, Dawkins calls Islam as evil!
http://www.youtube.com/watch?v=Qhp5ktBSsu8
Dawkins will never criticize Islam.
If he does, Muslims will kill him.
Just made for each other.