For those of us who have lived the whole cycle of the UFO phenomenon, I highly recommend "The UFO phenomenon" a book by John Greer, "The Archdruid". The book is also summarized in a post of his.
Greer is a lucid thinker, an excellent analyst, and his knowledge is truly encyclopedic. The result is a book that, as it could have been expected (and as he himself describes) "managed the not inconsiderable feat of offending both sides of the UFO controversy. It did so by the simple expedient of setting aside the folk mythology that’s been heaped up with equal enthusiasm by true believers in extraterrestrial visitation and true believers in today’s fashionable pseudoskeptical debunkery."
It is not often that a book can change one's worldview, but this one did that for me on several points. Greer is completely right in noting that the UFO phenomenon - as others - have given rise to a wave of "pseudoskeptical debunkery." The concept is that often scientifically minded people have gone too far in their criticism of anything that appears to be outside what we consider the realms of science.
One of the problems considered by Greer is disinformation, that is the willful distortion and misrepresentation of the data. It is something that plays an important role every time we move away from phenomena which can be comfortably reproduced in a laboratory. But scientists have usually no training and no experience in recognizing disinformation and dealing with it. They just tend to ignore it, and are easy victims of its effects. On this point, the discussion in Greer's book is excellent and brings overwhelming support to his conclusion that the UFO phenomenon is mainly the result of disinformation created by the US military.
Another point raised by Greer is how the debate on UFOs has been framed using different views on how to obtain knowledge (if you like, it is an epistemological problem). Believers in the extraterrestrial origins of UFO have been using rhetorical methods, debunkers have been using the scientific method. Greer correctly notes that there is an abyss of difference in the two methods. Science tries to verify a theory by falsifying it and just one experiment that goes against the theory will destroy it. Rhetoric attempts to buttress a theory by piling up positive results and neglecting negative ones. When we get to debating UFOs, debunkers are at a definite disadvantage as they have to prove that all sightings are illusions, or hoaxes, or known flying objects. It can't work.
So, if someone says that he has seen strange lights in the sky, it is silly to feel that a scientist's duty is to automatically dismiss that by saying that it was just the planet Venus or something like that. That doesn't mean that we have to cede to the tsunami of pseudoscience diffusing all over the infosphere, but science will lose credibility if it continues operating in the "automatic debunking mode". (See, for instance, this post by Paula). And if science loses credibility, it will become more and more difficult to demolish even clearly flawed claims, for instance about low temperature nuclear fusion.
The epistemological problems that Greer raises is profound and important. Suppose that there existed alien intelligences, and that it were possible to contact them, would the scientific method be suitable to study them? Hardly so, at least beyond a trivial level. Even studying the behavior of our own species - which we know to exist - turns out to be extremely difficult and easily affected by disinformation campaigns, as it has happened to "The Limits to Growth" study in 1972 and is happening now for climate science.
Modern science was born to study the motion of planets and to solve all kinds of mechanical problems. But, in time, we have been discovering how complex the universe is. Think just about this: we have good models telling us how human activity is changing the climate. But we have no good models telling us how to convince humankind that it is crucial to stop doing the things that create climate change. Clearly, we are missing something and something very important, which the scientific method can hardly deal with. The story of the UFO phenomenon is a reminder that we need - as always - to go beyond the old paradigms.
A previous post of mine on the UFO phenomenon.