Christian only groups?

I've attempted to join Christian only groups/chat rooms on the internet in the past, and it seems that they attract atheists and non believers by the thousands! I look for these groups and chat rooms so that I can communicate with people who have the same beliefs that I do, but I usually end up being attacted by people who are trying very desperately to voice their non Christian beliefs and it usually ends up with some of them using profanity, and hateful, negative chat. Why do you think atheists follow us to these groups so often? I used to think it was annoying, but in a way I think it's a good thing. THEY'RE SEEKING US OUT!...that's a start, right? They're at least reading what we have to say and communitcating with us. Whether it's to voice their own opinion or not, they're in a Christian group, so I say let's accept it. What do you think?