Internet atheists: Atheists don't say "there IS no god;" we simply lack belief, but we're not making any affirmative/positive claims, so we don't have a burden. In contrast you make a positive claim ("theism is true") requiring evidence and/or (depending on your definition of "evidence") (a) syllogism(s) which conclude(s) "therefore (some form of) theism is true."

Also internet atheists: In the same way that you lack belief in fairies, or in unicorns, or in Zeus.

Everyone else: ..... 

Internet atheists: ”what? Dawkinskraussdennetthitchensharris.”

Everyone else: Well, since we know (or at the very least have very good reasons for saying) that there are NO unicorns or fairies etc, then by drawing an an analogy between classical theism and fairies you are implicitly claiming that we likewise know (or have very good reasons for saying) that classical theism is false. That's more than merely "lacking belief;" that's a positive claim! Atheist and agnostic philosophers of religion who are knowledgeable of this field are more precise and less confusing in their terminology. 

Internet Atheists: DAWKINS DAWKINS DAWKINS!!! 😡