The trolling hypothesis makes the most sense to me. If these are non-terrestrial that means that getting here is relatively simple given the sheer number and variety that are reported. If that's the case and these things have no interest in colonization, resource extraction, or elimination of a competitor i.e. we are thoroughly beneath them in every way that makes me think the zoo hypothesis is the most likely, though I would rename it the natural park hypothesis. There's probably a big hyperspace sign above us that says "Don't feed the humans, please remain in your vehicle at all times, this area supervised for unauthorized contact attempts" and the trolling we see is the occasional harebrained tourist who wanted to tease the monkeys.
Hm, I mean I would agree this is the most reasonable explanation assuming the sightings are accurate, but you still have to question why none of them make more effort to communicate...
Something I and others like to do when visiting monkeys at a zoo is try to interact with them. You might not be able to have a full conversation with them, but they're still curious and interested in looking at objects and things you might have on you.
Why doesn't one of these trolls ever show us something really cool and definitively make their presence known? I just think if I were visiting the Earth zoo and I wanted to troll I'd probably do more, like put on a cool light show above NYC or something. It seems annoying fighter jets is probably one of the more stupid things an intergalactic troll could do - unless they're trying to provoke international conflicts or something...
You can always start believing some of the abduction and contact stories. A few of them are hard to dismiss, the ones of particular interest are unfortunately the ones where people have been physically harmed by the experience. There are also a small number of recovered material cases but most of them wind up with the material going missing at some point.
If you want a reason to believe in cover ups and the governments actively hiding this stuff just imagine what it was like for the native Americans to come in contact with Europeans for the first time. There might be a good reason for there to be efforts on both sides to prevent contact.
