I don't necessarily believe that "eye for an eye" is always applicable.  I do, however, believe that some should be subjected to the same or equal when compared to what they have subjected their victims to.  For example, child molesters.  That is a discussion I could get into without an end any time soon.  Now, with regard to the question as to whether or not people can change or if they deserve treatment....Yes on both counts.  For some people their issues are based on a chemical imbalance.  For many, their issues are rooted in psychological issues that often stem from outside influences.  In many cases, therapy and outside continued treatment are effective.  Quite honestly, I feel that it should be addressed on a case by case basis.  Not all are the same.  Furthermore, while I do believe that "eye for an eye" is justified in some severe cases, I struggle to find justification for such severe methods as those practiced in the movie.