I do love a false equivalency. While I don't think it is the duty of any given Muslim to condemn any given Islamic attack, Islam literally has a set textbook for its adherents. Many interpret it differently, but its followers in general share many beliefs and engage in many of the same practices. Atheism is not a religion or an ideology or even a movement really; the only thing its followers generally have in common is that they don't believe in a god.
In any case, obviously I condemn it, because I'm not bats**t insane...