The religious world has a problem with cults. That is that sometimes straight fraud, and other times the Dark Side has powers that can fool people. This is the reason the Gra signed the famous letter of excommunication,--to warn people not to be fooled. But after him, Rav Shach also stated the same warning. And also Rav Israel Oddeser of the Na  Nach group. But for some reason their warning went largely unheeded. [Rav Nahman I should mention not only was not included in the excommunication but also stated the same warning. עיין השמטות של חיי מוהר''ן של רב שמואל הורביץ See left out portions of the  Life of Rav Nahman of Shmuel Horvitz.  Not the left out parts that were eventually published but rather the left out parts that were collected separately. and never included.