It's only in the last few years that I've found a bunch of atheist groups on the Web, complete with Facebook pages and so on. I guess I just wasn't looking for them. My first reaction to this discovery was a sense of curiosity, because I'd been pretty much content with maintaining a relatively low profile regarding my own lack of belief in a deity. I wasn't hiding my lack of belief, but I wasn't advertising it, either. I became interested to learn what others who shared my atheism thought about various things. Looking back, I suppose I shouldn't have been surprised about what I discovered about the atheist 'community' - atheists are about as far from being a community as it's possible to be!
To have arrived at atheism, it seems pretty evident that you have to be (or become) a freethinker - someone unwilling to put doctrinaire boundaries around where your thoughts lead you. Thinking for yourself has to be a habit for you to be an atheist. The only thing atheists necessarily have in common is their shared lack of belief in a deity. When you look at the group of atheists as a whole, the things we do believe in are all over the political, social, and personal spectrum. To convince yourself of this, spend some time lurking in an atheist discussion forum. The minute anyone puts out some sort of statement of belief (as opposed to a statement of unbelief), it's almost inevitable that someone is going to pop up and dispute that statement in some way or another. The arguments are incessant, with some people lining up on one side of the discussion, even as others are vociferous proponents of the other side. And there may be many who choose to advocate a position in between the polar opposites of the argument.
Although I find most of these bickerings to be boring and concerned with trivia or things I consider to be outright nonsense, I've come to cherish this aspect of being an atheist. Atheism has no sacred authorities (although many atheists have high regard for this or that prominent atheist - like Richard Dawkins or the late Christopher Hitchens), it has no sacred scriptures (although there are books out there that many atheists find inspirational - like Al Stefanelli's Free Thoughts), it has no doctrine, no listings of core beliefs to be recited, no churches, no tax exemption, no pilgrimages, no ordained priesthood, no seminaries, no hymns or chants, no liturgy, no dogma, no ... well, you get the idea. Atheism allows you to come to your own conclusions about anything, by whatever process you choose. There's no ultimate authority in atheism to decide the issue in a clash of ideas.
Nevertheless, there are certain characteristics that seem to be fairly widespread amongst atheists: we usually prefer the kind of freedom of thought and expression exemplified so well by the U.S. Constitution and its Bill of Rights, we mostly hold discrimination against any group of people in contempt, we tend to respect the sciences as the apex of successful rational thinking, and so on. Politically, we often are labeled "liberals" without regard to our actual political beliefs. Socially, we often are outcasts, despised by many believers, which may include friends and even family members who have forsaken us when we declared our atheism openly. But none of these characteristics are universal in the atheist 'community'. There may be an "average atheist set of beliefs" but most atheists would disavow one or more elements within this average set of beliefs. It's a movement without constraints on your opinion about anything!
It's natural to suppose we would seek the company of other atheists as a shelter from the believer-dominated society all around us. But whenever we come together (physically or electronically), it seems that our shared lack of belief is not enough to unite us for long! When we learn what other atheists believe, it's our habit to challenge those beliefs that we don't share. And those arguments frequently turn into invective and insults - we're humans, after all, with human failings. Of late, there has been a big argument within our atheist 'community' wherein some women feel that the atheists around them are behaving like bullies or worse toward them, simply because they're women. I can't say the extent to which those perceptions are accurate, but it's logically possible that the set of all atheists would include some people who are insensitive to things that women might find to be offensive. Further, it's not possible for me to dispute a perception - it necessarily is whatever it is - but if the perception has a factual basis, it likely isn't entirely representative of all atheists, or even all the atheists in a particular group. This apparent 'schism' in our 'community' is taking some atheists down a path that incorporates adding a set of core 'beliefs' to atheism, referring to the 'new atheism' as Atheism+ ... that is, atheism plus a set of shared beliefs (with the added implication that this is a positive thing to do). I refer to this as an apparent schism because our community is not (and never has been) at all unified about virtually anything - one more crack in an already thoroughly fractured group isn't particularly meaningful!
I suspect this effort to graft beliefs onto atheism will end in failure, because once you have a set of beliefs, you've added dogma to a community of people very much prone to arguing and bickering about damned near everything. The new movement will fractionate just as religions inevitably shatter into multiple denominations because of clashes about doctrine/dogma. We atheists struggle as a 'movement' because of our seemingly incessant need for disagreement among ourselves. This penchant for disagreement saddens me somewhat, because it turns friends into enemies and cripples our ability to take action to further causes in which we believe. Ultimately, I have to accept that freethinkers are very much prone to being argumentative loners.
In my life, I've tried to avoid being a 'joiner' - for the most part, I prefer not to identify myself with this group or that because virtually all of them contain elements with which I disagree. I don't like to be bound by doctrine I didn't create myself and I prefer to feel free to say what I think, which often includes critical comments. I'm not particularly worried about hurting someone's feelings with my criticism if they're adults and capable of independent thought - I'm no fan of being PC! I'm an atheist, and I'm not generally willing to let counter-arguments offend me, although at some point I might get bored with them.