I frequently look at atheist blogs such as freethought. Some of them are interesting, well-written, providing useful bits of news … some of them post pictures of their beautiful pets.
Occasionally a naïve newbie wanders in and tries to explain to atheists that Satanists do not worship Satan. S\he gets run out of town.
Some of the top atheists are too intelligent not to have read the Satanic Bible. However, it is certainly not in their interest to enlighten their sheeple.
If I joined an atheist organization, despite the fact that I have no hostile intention whatsoever, I should feel that I was walking on eggshells.