Treat Techniques as Firearms?

I don't know about treating them like firearms, but I use much discretion about what I teach to whom. It would be hard to live with consequenses if student's or worse observers try something that hurts, or kills another. I have a technique I have taught to exactly 5 women in 40 years, but those five women are almost rape-proof. Each of them had to earn the right to be taught this life-saving technique, because of the danger inherent in it.