But I don't understand why you think vigilante = the eradication of the problem
Because you're a man of hope, or of cope.
If you are a man of hope, you have my respect, especially in a day and age where trusting the system to do what is supposed to be done held equally and unilaterally to the letter of law regardless of politics or social take. That the law can and will, and should, provide proper justice when it is called upon.
If you are a man of cope, then you have my patronization of this, especially in this day and age, where you're not willingly trusting in the system itself, but rather in the people within it for your own reasons. That's silly, people can and will often disappoint you on a regular basis, you shouldn't project your own subjective viewpoint on a system that is meant to be definitive, it's how you get the current day and age applications.
Vigilantism is an answer to those two situations:
When hope is lost, and the unilaterality of the law is lost, to the point where justice is forgone altogether, then it rests on the shoulders of the citizen to apply the proper punishment according to the letter of the law. Aka "Judge and Sheriff are dead? Cool. You're the Judge and Sheriff now, abuse your power and we'll kill you." That's how it's been for hundreds of thousands of years, and that will not change, nor will it be shamed.
When cope maxes out on someone's end, where they cannot cope anymore, that's when we see people doing rouge vigilantilism, because people are not longer able to cope, because their subjective of justice and righteousness is not being met. Which is explainable in this current day and age; however, this has no bearing on what is supposed to be the unilaterity of the Law.
It's like this.
"A pedophile who is released on a technicality from a court flub up or a corruption of a sitting judge, or a bribe is a miscarrage of judgement"
What you are not allowed to do "Shoot this man as he walks out of the courtroom"
What you are allowed, and are tasked with doing "Monitor this man, if he attempts to do a crime again, then collect that receipt. If they are threatening the immediate life of another or yourself, you may kill them as is your right."
That's considered "Look the other way vigilantilism" or "Being a good citizen, filling in the cracks where the law fucked up.
An example of incorrect vigilantilism.
"A pedophile is given 2 years of time, due to a corrupt judge, the pedophile serves a year."
You stalk the pedophile, light his house on fire, and then lynch him, hanging his body in the town square, and with his limbs scattered about the town.
While it sends a very strong message, your response is ultimately subjective in that, and will land you prison; however, if that's the attitude that everyone takes, you can be rest assured there'd be no pedophiles in your area, at least, not any out loud ones.
We also run into the problem of "When does personal subjectivity override the unilateral nature of the law? Let's say you're like me, where you monitor peope. Where do you apply softer and harder? Do you apply harder when they are Black, Muslim or Gay? Do you apply softer if they are Family, Jewish, or Friends? If you truly wish to be unilateral; you must remain neutral to all matters in that; of which, is rarely seen in incorrect vigilantilism; which is often fueled by a subjective that bleeds over into the act.
Should we kill pedophiles? Should we kill terrorists? Should we kill neer do wells? Oh absolutely, a little bit of the fear of Death sets a society straight very quick; but where does it end? We can hand draw quarter while gibbeting the pedophile, we can immolate the terrorist and impale their head on the spike, we can disembowel the rapist, the molester, and flay them alive. What about the theif? The pirate? The copyright strikee? The jaywalker? The non recycler? The person who said blue instead of red?
Don't get me wrong, a little bit of fascism in regards to heinous things is effective; but it's a slippery slope; and I've neither hope nor cope in my fellow man to keep themselves from becoming the monster they fight unless they are like me, "Removed from subjectivity, and simply handing them the receipt of their acts as properly recorded and scribed."