Choosing a self-defence course or martial arts instructor

Many martial arts fakers teach unrealistic and often foolish techniques. For example, it's good to learn how to knee an assailant in the groin, but it becomes instantly dangerous if they claim that these techniques can equip you with the skill to overcome multiple attackers.

You should be aware in what discipline your instructor trained. You want to take a self-defence course at a martial arts school that offers instruction in a specific discipline.