Many Satanists identify as Atheist. It's a term to denote that they don't believe in any god, devil or such in any literal since. I, however do not like the term Atheist any longer. This is thanks the groups like the American Atheists and their ilk. These "Atheists" have given the impression to many that Atheists are liberal, state worshipping, democrats that have gay sex with the Humanist camp.
These "Atheist" groups are anything but atheists. They have simply turned the Christian god into a Government. They cherish the weak. Always in the hunt to raise taxes to provide more food stamps and welfare. They whine and bitch for increased government and vote vote vote for the next lesbian or fag running for office waving a rainbow flag.
Satanism is about worshipping yourself, not the state. We aren't out there asking for food stamps and working in soup kitchens. Charity is seen for what it is a handout to the dregs.
I foresee a large scale increase in those who identify as Satanists as more and more people become sick of the liberal agenda of the Atheist camp.