They can be corrupted by teaching one's version of Gurdjieff's teaching in a way that distorts it and in a manner that hurts people, especially with a brutal process Gurdjieff used to call "SHOCK treatment." In the distorted version, it settled into a sadomasochistic cult with the cult leader doling out shocks and the "students" yearning for those painful shocks to the extent that those who were never given those shocks considered themselves to have been overlooked and cheated out of what was thought to be a highly valuable experience. It was very sick. You know full well who I'm talking about, but I'm not going to mention the name of this person.