Not useful for everyone

Who such a thing carries with him, should therefore be able to deal. Leading the screen just to feel more confident with it, is counterproductive, because you trusting in the security Deceiving the screen does not do in an emergency, what is the safest, namely run.
Who mastered combat techniques with sticks, so, however, can already cause some damage. A beginner will only remove the screen, and in the worst case he is then beaten so himself.