The ethics of the situation only comes in place when some form of system is already in place. If we were living in a lawless society or in caves, off course then everyone could and would come up with their own version of justice and this question would not be a valid one.
Again, I was not talking about the legality of the act, I was talking about the ethics.
For example, do you think that Robin Hood was a kind of person our kids can learn from, if we read that story to them?