For centuries, humans have experienced and explored strange experiences perceived as supernatural or paranormal. In the 21st century, reality television and the Internet boosted public interest in ghosts, UFOs, mystery animals, and unusual phenomena worldwide. By 2010, there were about 2000 self-formed amateur research and investigation groups (ARIGs) in the US whose goals were to "prove" paranormal activity existed or help others who have experienced such events. The ghost hunters, Bigfoot chasers, and UFO researchers were serious in their pursuit, calling themselves professionals, using an array of equipment, and stating that their methods were scientific. High regard for scientists and the honorific use of science in American culture, coupled with the public's lack of familiarity with scientific methods, created a niche for self-styled paranormal experts to become locally and nationally renowned, often assuming the scientist role without having scientific training or credentials. This volume is a fully-referenced, comprehensive and unique look at the history of research into these paranormal topics by scientists and the mission, methods, and ideas promoted by passionate amateurs.