Some say shadow people are simply ghosts that don't have enough energy to manifest, others say that shadow people are evil entities...yet others claim that shadow people are beings from another planet, but what I know shadow people to be are beings from another dimension within our own planet...they are not aliens from another galaxy or planet, they are not demonic beings or angels. Shadow people are from another dimension and time who are curious about us and our ways...they are sort of a spiritual spy and that is the reason they appear as a dark shadowy figure that we can not see directly, they are advanced beings that move to fast for us to catch with the naked eye, and we can not see their actual form because again they are to advanced for our minds to comprehend and so our eyes only see half of what they truly are because our eyes are not getting the actual information from our brains because our brains don't understand and they move to fast.
I have spoken to allot of people and the most common reason why people think they see shadow people is because they are being stalked by an evil presence which is very far from the truth, shadow people or extra dimensional beings are far from aggressive and/or evil, they simply want to understand life just the way we want to...they research the same as we do, they also observe us in order to find a way to best communicate with us, and share what they know and can do...they mean us no harm and only wish to participate in a world that is much like their own, they can not interact with us and/or influence our world, they can simply exist and evolve further just as we do....that is of course until we are both ready and willing to accept alternate reality's.
Why we don't see them directly? one reason is as explained above, they are to advanced and move to fast but also, think back to the many television shows that involved time traveling and the like...what has always been the most common no-no? if you said interacting with the past then your right!...well shadow people work in much the same way, they can not influence our world in any way period so they must act in a sneaky manner in order to learn without disruption, they also act in a secretive manner in order to alert us of their presence and of future dangers to our existence..why? because before they ever even think of making contact with us they need to make sure we are ready and I know that sounds a lot like aliens, they are not aliens they are beings who long ago evolved way beyond our understanding and time, these beings were once human and existed along side us but in a different alternate reality.