Those Theists

[vulcanlogician]

“You kind of have to believe in "something" for there to be internal disagreements about that "something". Atheism isn;t about believing in something. See the disconnect?”
—Khemikal

Not really, it seems to me that believing in no god is believing “something”.  

Is not playing baseball a sport? I don't play any sports (I'm a bookish nerd), so does that mean I play non-baseball? No. I simply don't play baseball. In the same way, agnostics and atheists are nonbelievers--and their nonbelief isn't a belief system in itself. It's a lack of one.

You can take individual atheists and ask them "Are you a materialist?" If they say, "yes" then that (materialism) is a belief that they have. Certain truths necessarily follow from that belief.

Same goes for evolution. Most atheists accept that life evolved to its current form. If someone makes the claim, "Life on earth evolved from simple proto-organisms to its current complex state," the burden of proof is on them to prove it. Evolution is a positive belief. Atheism is not.

Belief in Santa Claus is a positive belief. If you think Santa Claus doesn't exist, that doesn't mean that your non-belief in Santa is, in turn, a belief in something. And you don't have to prove Santa doesn't exist. If a person claims that Santa is real, it's up to them to prove that he does.