They do not slaughter animals. Like the Wiccans, many Satanists find truer companionship from pets than from humans. One couple I know purchased a hearse as their family vehicle. The ritual practiced by Satanists seems solely a form of self-enhancement. Students are most earnestly warned against attributing objective reality or philosophical validity to any of them.
Many atheists demand that others stop misrepresenting atheism.
We are not self-consistent if we misrepresent others. It's also good to know the true sources of evil. To start with, we could study the beliefs that inspired the Inquisition, and the thinking that ended it. We can work to end the Taliban regime in Afghanistan, and to prevent similar madness at home.