It depends on what you mean by "do something". If you mean revenge, or some form of it; that is not what Christ would have of us. That's for natural man.
Personaly, and I think the bible backs this up, revenge is not our right. It's God's and God alone, who holds the right to avenge. Justice? Well that's another issue. But which is it? Justice or Revenge?
It has to be justice, as nothing should be done other than for the sake of God ideally. However what God has allowed is fair game, and some revenge as I see it is allowed, like for instance a prayer against the person who wronged you, though the prayer itself should be equal to what you were wronged with. Of course if that's a fellow believer, really one should forgive, but it is allowed. Some people believers and otherwise transgress bounds and it may not be easy to overlook. But really justice can look like "revenge", so for instance if there's speech of a death penalty, one can see that as revenge, but if such is what God commanded, it does not matter what anyone sees it as because it would not only be correct, it would be just because God is Just.
Revenge and Justice are not synonymous terms.
Justice; is Just behavior or treatment.The quality of being fair and reasonable to a particular standard. Where as "Revenge"; is an action of inflicting hurt or harm on someone for a wrong suffered at their hands. As a "Verb"; it's to Inflict hurt or harm on someone for an injury or wrong done to oneself. They may seem similar, but the difference between Justice and Vengeance or Revenge, comes down to ones motivation or desire; which is clearly a matter of the heart.
So, in this way, they are not the same at all and there is a clear distinction between the two, but only to those who hold a heart for "Mercy". To those that don't, revenge and justice are the same, because when they offer justice, it actually revenge. This can be seen as righteous, but only if the one who offers it is righteous to do so; this is to say they hold the standard. In Christianity, that's God only. For those directly under the curse of the Law of God it's seen as more of a cooperative between them and God.
Obviously we administer Justice in mans law, but for many this is not enough. Take murder for example. Is it enough to kill the murderer? It may be just and it should be, but does it satisfy revenge? Who kills the murderer and walks away satisfied that crime committed by the murderer has been revoked in some way? It does not reverse the crime, bring the person murdered back, or sooth the heart of those hurt. Because this is true, revenge does not satisfy, it simply grows, and justice can not be dealt with a heart set on revenge.
This is illustrated by Paul in James 2:10-13 (NIV) 10 For whoever keeps the whole law and yet stumbles at just one point is guilty of breaking all of it. 11 For he who said, “You shall not commit adultery,” also said, “You shall not murder.” If you do not commit adultery but do commit murder, you have become a lawbreaker. 12 Speak and act as those who are going to be judged by the law that gives freedom, 13 because judgment without mercy will be shown to anyone who has not been merciful. Mercy triumphs over judgment.
Those trying to keep the law of God are fully under it and must keep all of it to the letter, because if they are guilty of any of it, they are judged under all of the law.
To those that follow Christ, Christ is not just a profit; He is God himself, and offers mercy to those who have faith in Him, and what He's done to purchase them. They understand that they can not follow the law, and in fact no man can. It is for this reason that He is the only way to salvation, under the law. Therefore, because we are offered mercy by God through our faith in Jesus Christ, we offer mercy to others through Jesus Christ, not ourselves. Because as Paul says; "Mercy triumphs over judgment." Revenge is worthless.