The idea of UFOs as metallic ships sent to Earth, piloted by intelligent, flesh-and-blood beings, is not only not supported by the historical documentary evidence, but it also makes absolutely no sense whatsoever based upon their behavior patterns.
They fly all the way here, over astonishingly vast distances, occupying EONS of time, and all they do when they get here is violate the... umm...."privacy" of a few hack science-fiction writers or conniving lumberjacks?
And the whole business of the "aliens" having some kind of secret, sweetheart, "handshake deal" with the Government bigwigs, that allows them access to as much booty as they can probe, and supplies them with a huge, rent-free, utilities-included underground lair like Goldfinger had in that James Bond movie, to hold up in between forays out into the night, for more below-the-waist scientific "experiments" on the unsuspecting and unwilling subjects? Well, if they are advanced enough to GET here, either through time (a LOOOONG time), or interdimensionally (extremely unlikely, but still more probable), then they don't NEED Uncle Sam's permission to do ANYTHING, thank you ever so much.
And the level of abductee-related experimentation is so crude as to be laughable if it wasn't so vile; how many asses do they really need to probe? And why are they so hung up on the ass? You never hear about them examining anybody's ears, or nostrils, or hands. It's always the ass.
What cable channels are they getting in outer space, anyway? Even a species as comparatively backward and crude as our own can find out virtually everything we need to know about a lion's ass by catching and tranquilizing a half-dozen lions. We also have the technology to make said examination painless, and completely unavailable to the lion as an experience or a recovered memory, with drugs we invented, and have been using, for decades.
Are we to assume the aliens are smart enough to get here, but too dense to realize that, after assembling a comprehensive database (at great risk of discovery) of human asses, that they all work pretty much the same way, and that you can synthesize drugs that make your presence in and around those asses completely unknown to the subject of your fin de siècle, morbid, depraved, hijinks, the owners of those over-examined, alien-plundered, asses?