This is not to say that they are nothing but folk memories of past humans...as promoted by Margaret Murray in her writings in The God of the Witches. The Picts, who she claims they were, were not the backwards, peaceful people she makes them out to be...nor so "lost" as she seems to have thought. They were a Dark Age historical people, who were great warriors, and probably either Celts or Germanic. They are clearly of the Otherworld...although if they choose they can indeed touch this one.
And they can intermingle their blood with ours, and have. Many Scottish and Irish families make such claims. The taking of a Fairy lover was much written about, as was the taking of human children by them. And the leaving of their own here. In fact folklore shows a great deal of intermixing between the Sidhe, the Gods, and humans....something that may indeed still happen. Or so I believe...and even hope. Or perhaps fear.
Fear we should, for our concerns are not often theirs. And our kind has done more than forgotten them....which alone does not bring their demise, we're not talking Peter Pan's Tinkerbelle here, they don't need us to remember them. They need the world to not be destroyed. For our world and theirs are forever intertwined....and what we do here, affects them. I believe this thoroughly....and fear what we have done more than I fear they're retaliation.

And like all beings, there are those who are our friends and those who are our enemies. Within their own world there are wars and hatreds. Perhaps we are not the only ones bringing destruction...perhaps those destroying the rainforests, polluting our air, poisoning our waters have allies in the Otherworld themselves. All the more reason to become allies with those who are fighting to stop it in both worlds.
As we do not know how any of them may feel towards us in particular (although we may know some of them personally) it is traditional to refer to them as the Good Folk, the Fair Folk, or the Good Neighbors....in hopes that they might be. And as to refer to them by a name may indeed call their attention to us and that may often be asking for trouble. For as I noted, their agendas are their own.
I do not worship the Folk nor do I believe in them as if they required belief ---no more than I "believe" in humans. They exist...this I take as fact. And I may honor some of them...as they have been good neighbors and hospitality is important to maintain. And some of the....some of them I love fiercely...and have since childhood.