The terms alien abduction or abduction phenomenon describe "subjectively real memories of being taken secretly against one’s will by apparently nonhuman entities and subjected to complex physical and psychological procedures." People claiming to have been abducted are usually called "abductees" or "experiencers." Typical claims involve being subjected to a forced medical examination that emphasizes their reproductive system. Abductees sometimes claim to have been warned against environmental abuse and the dangers of nuclear weapons. Consequently, while many of these purported encounters are described as terrifying, some have been viewed as pleasurable or transformative.