All anecdotal events of "close encounters" are discredited primarily because they are reported by unreliable witnesses--those with unstable lives, chemical dependency issues, rednecks. Surely, we are told, if the aliens wanted to contact us, they'd get in touch with the world leaders.
But somehow, we got through eight years with Bill Clinton in the White House with nary a peep from the aliens.
So where were the aliens then?
QED.
Cheers!
Wait a MINUTE! I remember a former President claiming a close encounter:
Seriously, didn't Mr. Peanut claim a UFO encounter?