These became legal to own in my state in 2013, so I decided to actually get one myself.
I actually used one in 2006 (not knowing that it was… not legal at the time) when my apartment was broken into, and the door busted down, when it was all that I could grab to defend myself with. The intruder knew that it was illegal, even though he ran out of the residence screaming. When police eventually arrived, he told them that I was in possession of an illegal knife. Funny that, given that he kicked down my front door. The police didn’t care, and they told him this, as they handcuffed him… and they made sure to tell him that they did not care because he had kicked down my front door. The knife in question belonged to the other resident of the apartment, who was not home at the time that I had grabbed it, when the intruder actually kicked down our front door. Needless to say, I did not get in trouble for the weapon that I had to grab to defend myself in the heat of the moment, although I made sure not to own one myself until it became legal to own one in my state, which it now is. As a result of that law changing, I now have one in my… arsenal…
When it comes to defending me and mine from the threat of harm, I will do so without any hesitation at all.