First, let me say that I've read some weird stuff in my life. I'm ok with strange or outlandish claims. I've read Charles Fort, John Keel, Phil Dick, any number of conspiracy books, UFO studies, bigfoot, ghosts, goblins, on and on and on. I'm no stranger to the kinds of stories told in this book.
However, I really wanted the narrator here to be more skeptical. There were parts of the book where he neglected the obvious explanation for things (that the subject of the book, the narrator's friend Dion, is, in fact, mentally ill) in favor of what he considered the only 'logical' explanation: that his friend was actually being stalked by midgets in invisibility suits, hounded at every turn and driven to the brink of insanity by hundreds (thousands?) of government agents assigned to pester him 24/7.
I've read a few accounts of gangstalking, and Dion's claims (as suspect as they are, even by the narrator's own admission) fits in with that schema. But, at the same time, I tend to see claims of gangstalking as evidence of mental illness. Let me be clear: I'm not diagnosing anyone as mentally ill, but it's really a better explanation for Dion's experiences than the ones unflinchingly accepted by the narrator. Because the narrator barely raises this or explores this as a possibility, he comes across as unreliable, which isn't something you really want for a book that purports to be nonfiction, a 'true' story.
Aside from that, this book should have been much shorter/better edited/generally better written. There were entire swaths of transcripts from phone conversations, for example, that added virtually nothing to narrative. If the writing was better, this book might have deserved an extra star.