Who are these "many atheists"? All of the atheists I know (including myself) hardly ever talk about it, especially to people they know are religious. The reason is simple: it makes an awkward social situation. I think it would be better if atheists were more vocal about their atheism, but I don't volunteer that information unless somebody asks.
Look around. This forum is populated with people that can't let the word "God" or "Jesus" slip by, even in a non-religion oriented post, without some remark about how stupid it is to believe in a god or "God". One poster here doesn't like their country's national anthem because it mentions "God".
I'm guilty of it myself, but I'm trying to break the habit, because it's annoying. I'll dig you up some examples to forestall the cries of "EVIDENCE!!" if you'd like. Pretty sure I saw one today.
Axiom_Blade said:
Contrast that to the many Christians who not only feel comfortable talking about their religion, but actually volunteer that information whenever they get the chance. I've even known people who manage to shoehorn Jesus into any conversation you get with them. I've never met an atheist like that. This is because society has a different message for atheists than it does it does for the religious. That message is "shut up".
I wish they'd shut up about it, too. None of my business and I couldn't care less what religion someone is, unless they take a fancy to worshiping me!

I hear the donation plates can be quite the haul.
Axiom_Blade said:
Being an atheist is, in some ways, like being gay. You're supposed to be ashamed of being an atheist. You're not supposed to talk about it.
Don't be ashamed of it. Talk about it if you like, but it doesn't need to be interjected every time someone mentions god
*. If a Christian/Jew/Muslim/Howieite did this people would be screaming for his blood, and rightly so since it's annoying as all get-out.
*I'm not accusing you (Axiom_Blade) of any of this, I'm just mentioning that we (atheists) as a group could tone it down a little. The smug, know-it-all atheist stereotype didn't just appear out of thin air.
Who knows, maybe I'm totally off-base here, but I don't see the religious people changing their views based on our actions, so we might as well make our actions at least tolerable to our own kind.