Some of the anti gun and anti self defense people tend to confuse being a vigilante with defending oneself. There really is no connection between the two, as vigilantism is a crime, while self defense is a basic human right.
Vigilantism
A vigilante is defined as “a person who violates the law in order to exact what they believe to be justice from criminals, because they think that the criminal will not be caught or will not be sufficiently punished by the legal system.” In other words, vigilantism is when a person believes that a crime has already occurred, and goes after the criminal in order to punish them. Vigilante “justice” is wrong, and a far cry from actual justice. It deprives the accused of their right to a fair trial, and often results in the innocent being punished. It also tends to result in extremely inhumane and grossly disproportionate punishments being inflicted. Although I could write pages and pages about the historical (and current day) atrocities that have been committed by angry mobs of vigilantes, the point should be clear: the administration of justice is best left to a detached and impartial court system, headed by experienced judges, rather than angry members of the community.
Self Defense (and defense of others)
Self defense, on the other hand, is defined as “the right for civilians acting on their own behalf to engage in violence for the sake of defending one’s own life or the lives of others, including the use of deadly force.” In other words, self defense is the use of force to stop a criminal who is currently committing a violent crime, in order to protect oneself or another against that immediate violence – rather than to punish the criminal. Self defense is a good thing. It allows a person who is going about their peaceful business to avoid being injured or killed by a violent criminal. Self defense is endorsed by peace loving people such as Pope John Paul II, the Dalai Lama, and Mahatma Gandhi. Self defense is also morally right as a philosophical matter, using tests such as those laid out by Immanuel Kant. Finally, self defense is recognized as a legal right and human right, and has been for virtually all of human history.
I hope that clears things up.