" those who believe in them have to do so on faith a religion"
That's not true.
Witnesss are OBSERVERS.
Observation leads to a collection of cases all with the same basic principles.
Either ALL witnesses reporting seeing men in black are all having the same hallucination; or they all witnessed it. Period.
It has nothing to do with faith OR religion; and to suggest (again) that this a belief or a religion to me, belies your own Superstition. Just becaus you can't see into the astral doesn't mean it doesn't exist.