They are not all dangerous or evil . Some are quite open as to what they do , and why they have such peculiar practises.
The ones that get our attention are the ones that are run by unscrupulous people , and usually end up murdering there members , or condoning sexual abuse , rape , extortion , deceit , fraud , robbery...
The general view is that people who run a cult or a sect , are doing so for money or some other perverse gratification , or even that they are mentally imbalanced. "Dangerous" because cult members are stereotyped as gullible , naive looking for attention ,wanting to belong , easily manipulated to the point of committing murder or loosing their own lives
there religious sects are lame.
Bill Evenhouse has written: 'Sects and cults with Christian roots' -- subject(s): Apologetics, Christian sects, Cults
David V Barrett has written: 'Sects, 'cults' and alternative religions' -- subject(s): Religions, Cults, Sects
religions, sects or cults which have evolved from Sihkism
Marcus Bach has written: 'Strange sects and curious cults'
By some, yes. In either cults or sects of "pagan" origin.
Christians
John A. Saliba has written: 'Christian Responses to the New Age Movement' 'Religious Cults Today' 'Psychiatry and the cults' -- subject(s): Bibliography, Periodicals, Indexes, Psychiatry and religion, Cults, Sects
William A. Young has written: 'The world's religions' -- subject(s): Religions, Cults, Sects, Religion 'Quest for harmony' -- subject(s): Religion, Indians of North America 'The world's religions' -- subject(s): Religions, Cults, Sects, Religion
Decoding the Past Cults - Dangerous Devotion - 2006 TV was released on: USA: 2006
Roberta Grillo has written: 'Attenti al lupo' -- subject(s): Cults, Sects
As vampires are mythical creature will little to no evidence proving their physical existence, I doubt there are any real vampire cults in the world. I would imagine however that there are sects or groups of people who adopt the vampire lifestyle, and they could be regarded as vampire cults in certain contexts.