Women as Witches, Men as Witches

I admit that I do not know a lot about real witchcraft - well, not real witchcraft, but more real than Disney movies.  However, I though I knew a fair amount about the basic lore, but I have never heard anything about using children's hands for magic.  And now that I do know, the thought disturbs me.  A lot.  Cutting off children's hands, and especially the hands of aborted babies, really makes my stomach turn.  It kind if makes me wonder about the people who came up with these ideas.  What was going through their heads when they made these accusations?  Another thing I decided I should have thought of was the Devil persuading witches to commit crimes.  Even though I have read things about warlocks and magicians using spirits to commit magic, for some reason I never made the connection between the Devil and witches before now.