When you run around the Lib/Prog playground, you are bound to offend somebody (or a bunch of them) eventually. The Atheists apparently did not find amusing the use of a non-entity as Gun Control tool.
You know the really sad part? That the Atheists behaved more like Christians than the so-called-Christian followers of CSGV did. But we agree that the do belong to a cult, so demonizing those who are not drinking their flavor of Kool Aid is not unexpected.