This is my debate topic. "Is vigilantism ever justified when the government fails to act."?

Self-defense ISN'T vigilantism, so don't try to be extreme. By saying oh if you can't use vigilantism then the World would be dead then you are lying to yourself, and everyone. So what it's ok for me to kill you to respond, so then isn't it ok for your family to kill me, which gets my family to go after yours. Never ending cycle of violence. An eye for an eye would leave the whole World blind, and on a journey of revenge be sure to dig two graves. Another quote to consider, History is written by the winners. So if you start going for vigilantism and you are the last man standing then you can easily justify that you were right all along, no one else will be there to argue.