Derek Murphy writes at Holy Blasphemy:
I went to Skepticon 5 expecting a group of heretics that would get a kick out of my inversed reading of Milton’s Paradise Lost, which claims that Satan is the hero of the story (which was actually the mainstream reading before it became the “mistaken reading”, and is now coming into vogue again by top Milton scholars).
I was surprised to find that Satan makes atheists uncomfortable. Atheists already have a huge image/perception problem, with the religious proclamations that people can’t be good without God and that therefore all atheists are “evil.” Christians already think of atheists as nearly synonymous with Satanists; hence atheists have an uncomfortable relationship with Satanists and don’t want to be associated with the Devil.
Even more so than the term “Atheist”, “Satanist” has an immediately powerful negative connotations. And on the one hand, I definitely think that those people who wish to create a secular political and social force big enough to stand up to religious groups that are trying to make their faith-based beliefs govern the private lives of the rest of us, need to think about how they are perceived because it does impact the message being shared.