I'm sure people saw something they can not explain, but that's the only relevation. One guy talking about knowing and having encoubters at night in his bed, clearing describing sleep paralysis. People are suggestible and have very different interpretations of unusual events and novel experiences. Unexplained doesn't necessarily mean extraterrestrial. This series tilts toward conspiracy and apocalypse cultures merging, and a subtle anti or post scientific pov. People are reaching for connection and creating these hybrid belief structures to replace what they have lost in traditional belief structures. Poignant, credulous revelations from real people and one or two skeptics or experts per episode to make it all 'fair and balanced'. Considering who some of the creative and productive crew are, you might think the final product would be better, but in the end it's just a more refined version of the traditional unexplained phenomenon media presentation that H. G Wells and Orson Welles proved was possible.