Is Wicca Satanic?
No. Wicca and Satanism are two entirely seperate, unique, and different religions. Wicca is a religion founded primarily on the published teachings of Gerald Gardner (though modern Wicca has gone in quite a different direction) whereas modern Satanism within the Church of Satan is derived from the teachings of Anton LaVey. Religious Satanists (not necessarily believers in LaVey's beliefs) follow a faith based on Christianity and Judaism, Wiccans, on the other hand do not believe in Satan. Satanists do not worship Satan (or Set) so much as a deity as they worship Satan as a principle. The majority of Wiccans worship the God and the Goddess as actual entities.
Many Wiccan concepts are completely the opposite of those believed in Satanism. For example, the Church of Satan advocates seeking vengeance, whereas the Wiccan Rede encourages forgiveness and letting karma and the 3-fold law do the work. We also share some beliefs, for example, we both partake in sabbats and neither Wiccans nor modern Satanists believe in Heaven or Hell. We also both have religions that are shrouded in misconceptions that result in prejudice.
Wiccans are not out to slander or try to convert Satanists. Our spirituality encourages understanding and tolerance instead of proselytization and persecution.