Someone asked me an interesting question today.
"Since you are atheist, do you think satanism is acceptable?"
Read it very condescendingly.
My initial response was "No." since I think that in 2010 we should all be rational humans and should be able to identify magic and religion as illogical. However, since we still have thousands of believers in this country, my answer would have to depend on what satanism is doing.
If the satanic followers are not infringing on others rights, not harming, or affecting anyone negatively, than it should be fine to practice what you believe. Most would have you believe that satanists are a real threat, but I haven't heard a word of someone identified as a satanist killing, murdering, or causing several problems for others. Not nearly as much as I have heard about religion. Religion overall (Not just christianity) has tried to tell people what to do, and punish those who don't. They praise and promote a book that lays it all out.
Regardless, that answer was not enough. They continued with "What about curses and demons? Satanism teaches people how to kill people using black magic."
Has there ever really been a curse that was effective? Is there any verifiable proof that shows someone died because another person drew pentagrams and said the magic words? No.
If someone wants to curse me, using their magic, go right ahead. So long as it applies to my rules mentioned earlier. If they don't need to do anything else but hold a picture with drawings on it and pray to a book to kill me, than there would have been a large following of magic users killing people.
So until a satanist revolution comes around, and begins to mercilessly kill people and infringe on my rights, feel free to worship.