Piffle!
Extraordinary claims require extra ordinary evidence:
And of course......
[1] Why only always single individuals or small groups of people that are witnessed to such events?
[2] Why most in out of the way places?
[3] why never ever any hard evidence? you know, bodies, excrement, other unearthly artifacts.
[4] Such Alien beings would be far in advanced of us and certainly not fearfull of us, so why the general "secret"type of visitations?
[5] Considering [4] why after so many thousands of sightings, have they not made their visitations official? [you know, appearing in front of the White House or Sydney Harbor Opera House forecourts]
[6]Why all the flittering in then flittering out again without any further contact?
[7] Considering [6] these beings have obviously travelled many light years, so again, why just flitter in then flitter out again, until the next so called visitation, when again, they flitter in and flitter out again.
[8]Why all reported Aliens are of the usual "Hollywood style"body shape and colour? You know, big head with big eyes, grey colour etc
That's just off the top of my head.....yeah certainly one great big fat yawn!