New Religious Movement
The phrase 'New Religious Movement' or 'New Religions Movement' refers to religions manifesting or experiencing their primary growth posterior to 1950, and these could include such groups as Thelema, New Agers, the Moonies, the Hare Krishnas (KCM), Wicca and Neopaganism, Satanism, Scientology, Erhardt Seminar Training, Druidry after Bonewits Aum Shrinrikyo, etc.
Several groups have been created by those spouting knowledge, some self-appointed scare-mongers such as Michael Warnke and Lawrence Pazder and those providing to civil authorities and the public in 'Satanism seminars' their pack of lies and Christian witch hunt propaganda as to the dangers of, and others legitimate academics, such as J. Gordon Melton and James R. Lewis), intending to educate about the religious character (through groups like the Institute for the Study of American Religion and the International Society for the Study of New Religions) what each called 'Satanism'.
In some high profile court cases, these variously credentialed 'experts' were responsible for sending people to prison for years (or preserving them from it in the case of the academics) in a travesty of the law. After such findings as by Kenneth Lanning and Robert Hicks, the folklorists went in to clean up the wreckage by deconstructing how the rumor panics played out (cf. the New York Folklore Society's analysis of the Satanic Panic in their local area, or the text by Best, Bromley and Richardson: The Satanism Scare.
Arguably the characterization 'new' is relative to the speaker or evaluator, and 'religious' is at points debated (esp. where some kind of remuneration transaction begins to make the phenomenon look more like a business or some other kind of social event). This focus of study and its raft of terminology was important in the dissuasion of anti-cultism and anti-satanism fomented on the ground level and in the courtroom, and served to undermine exaggerated assessments as to the social danger should these fantasy subversives remain unchecked.