Honestly, my point here is the same as in the thread on Noah's Ark. For the argument's sake, let's say that these "aliens" and "demons" are indeed one and the same (I have no idea and I don't care to argue about it). What makes you think they are indeed evil spirits? Couldn't the root of the "problem" be found in the mind of the victim?
See, I think some people jump to conclusions here. I'm not questioning all your quotes from the OP, for all I know, mysticism and aliens revolve around the same thing. But you assume that this means that these "demons" are entities in their own right, and exist with their own form and will, and they are here to do evil to us.
But how much of this comes from the mind of people? Our brain contains incredible power, for both good and evil, and we have power over our own situation. Can the mind not be driven to a point where you lack explanation for your experience? I think so, and the mind can create feelings of being possessed and other feelings like that.
