One of the biggest mistake people make about about atheists (or atheism) is linking them to specific ideologies like secularism or vegan-ism. You can be an atheist and believe in ghosts or magic or what not. Atheists reject only the concept of God. Now they usually make decisions based on scientific evidence and rationality, hence they tend to reject other superstition too but they are free to believe other things. For example- if a hypothetical tribe exists that believes only in magic but not in any supernatural being/God, they are atheists.
The burden of proof lies not on atheists but on the one claiming to know of the existence of a God. Atheism is not rejecting an already accepted god but not accepting him in the first place. Atheism is the default position.
Atheists can subscribe to any form of ideology (libertarian-ism, liberalism, conservatism). We are not Satan worshipers or baby Killers, we are just skeptical of the existence of God.