I'm sorry this might not be part of your expertise but can you know tell me as much as you about Satanism.
Thanx in Advance
Satanism refers to a set of religions in which Satan is worshipped and attempts are made to get him to do things for his followers. This often has to do with "pacts" between the worshipper and Satan, in which one rejects God and offers one's soul to Satan. There are many variations of Satanism, including a couple of organized "religions". Some Satanists see Satan as a nature god, while most view him as the one who rules hell and is the mortal enemy of God. Many Satanists believe they can influence Satan by blasphemy against God, by desecrating things used in the worship of God, and even by human sacrifice.
That being said, Catholicism recognizes that Satan exists, but also that Jesus gave his followers power to resist Satan. Catholicism trains exorcists to deal with cases where a person is "possessed" by Satan. There are very few cases where this actually has to be done, since most of "possession" is really mental illness; but there are definitely cases where exorcism has worked. Jesus himself performed exorcisms.
All that being said, to me it seems stupid. If someone decides to reject God and worship Satan, Satan has already won that person's soul. Why should Satan do anything more?