[cthalupa]

The problem is that "Technology allowing an advanced civilization to travel to Earth, enter the atmosphere, leave, etc." is significantly more complex than "Technology that would allow them to be completely undetectable to us, and also not crash into the planet"

"Only detectable by people with bad gear" is just not a technological state that makes sense in this context.

There is A LOT of stuff recording what's going on in the sky at all times. A lot of stuff that could give us detailed and high resolution images and other readings. Some of it is actively beholden to various governments so I guess you could argue it's being kept from us there - but are all of these governments going to be in lockstep on this issue? And even more aren't - are scientists going to all just keep quiet on this?

We've had all these declassified videos released recently, and they're some of the most obvious not-extraterrestrial-visitors ever. The one recorded on an aircraft carrier through nightvision with the flying triangles? Night vision goggles have triangular apertures. Bokeh takes the shape of the lens aperture - so bokeh lights become triangles. The blinking in and out of existence? Same timing pattern as a commercial jet.

The pill video from the jets? Parallax makes stationary things look like they move fast. The pill only ever looks to rotate/change direction when the actual recording device in it's housing also does. It's all stabilized so it's not readily apparent unless you know to look for it, but it becomes obvious when you do. What is the object itself? It could be a mylar balloon, it could be an IR hot spot from the sun reflecting off the water. Could be other things. What we don't have any reason to believe is that it is some sort of advanced craft with physics-defying maneuverability.

I fully believe that there is intelligent life out there. Probably in our galaxy, but near certainty in the universe. I also believe that the chances we have had intelligent visitors from another place is the barest fraction of a fraction of a percent.