Well... it's a merely anti-animal defensive object, and even should you happen to be forced to use it against a human being... how hard you think a human body is? Not to mention, should you use it to defend yourself against an attacking animal (a bear, a tiger, a lion, even a shark), it's the animal that throws itself over you, all you need is to raise the knife and it will get inside by the animal's own weight. You only need the blade to be inside your attacker for an inch, maybe less, to achieve the best results from the injection.
"It is criminal to teach a man not to defend himself, when he is the constant victim of brutal attacks. It is legal and lawful to own a shotgun or a rifle. We believe in obeying the law." -- Malcolm X
"We (atheists) act in good conscience because we believe in moral principles, not because we expect a reward in Heaven." -- Margherita Hack