The definition of a fundamentalist is someone who won't be swayed by evidence - someone who relies on "faith". This is in contrast to the nonbeliever, who relies on hard evidence and reason.
And believe me, the second an intelligent nonbeliever finds a good enough reason to believe in any particular deity, he will do so immediately.
But what sort of evidence would convince a religious person that his faith is false?
Look up the definition of fundamentalism in dictionary, folks. "Angry" atheists are preaching for rationality and a respect for evidence, not faith.