Cults and Quackery
In the US, there exists no governing body that specifically oversees the operation of martial arts schools. No certification, teaching license, or documented credentials of any kind are required to become a martial arts teacher. In other words, anyone can open a school and bestow upon themselves any title or rank they wish without intervention. Some instructors have claimed knowledge to secret techniques (okugi) that have roots to ninpo (ninja ways), yamabushi, or other esoteric warrior sects that typically have little to do with real combatics or anything useful. Dim mak (death-touch), hypnosis, or other magic tricks that are hawked are the stuff of snake oil salesmen, not real martial artists. Wackos that try selling this claptrap prey upon the weak and gullible and usually have no difficulty finding them. In my opinion, there's not much of a difference between a charismatic quack sensei and a pseudo-religious cult leader. Both types have an unquenchable desire to control, dominate, and eventually abuse their disciples. Quite often, these students lack so much self-esteem that they have no clue they're being manipulated and project unconditional authority onto a teacher with a distorted purpose and agenda.
"Train here and only here - this is the only art you'll ever need" is a common slogan of the cult school. A few years ago, somebody wisely left a kung fu/aikido "temple" when things got too weird. Dissenting from the Order was not taken lightly, and some of its loyal followers actually broke into this guy's house through his skylights in the middle of the night to illustrate he was still in dire need of self-defense guidance. Fortunately. he was able to fend them off with a sidearm and a call to 911, but he was badly shaken from the ordeal. Pathological cultists, like real martial artists, can be extremely dangerous.