Depends who you ask, Lots of people out there defining atheism,
  what atheists should do and such. They all have their own rules
  and tactics for whatever causes they're working on, all flying
  the banner of Atheism. You've got New Atheism, which has a
  series of typifications and leaders and stereotypes. You've got
  various "type of" atheists, all with their own definitions and
  stereotypes and such. There's plenty out there. It's like
  Protestantism. Pick one and run with it.   Atheism has a culture
  just as any other ideological groups do. Maybe from the inside
  you can't see it. But from the outside.. it walks like a duck,
  quacks like a duck, etc.   From an objective, sociological,
  behavioral point of view, Atheism is a religion. -   You can say
  "But we're not. It's not. Just look at our definitions." But
  when the rest of the behavior says otherwise... the words ring
  hollow. I'm sorry. I'm not trying to be mean here. -- I feel
  like I'm being mean here. I'm sorry - I believe in freedom of
  ideologies and that includes yours. I don't even know what mine
  is - I just let the facts as I find them pass through whatever
  methodologies I use to discern truth-values as best I can. But
  yours is stated and clear and I shouldn't try to dissuade you
  from the culture you've adopted for your own. I apologize as I'm
  not trying to convert anybody here today. --