It is very difficult to fight and prevent crimes, abuse and violence, when attitudes, social patterns and mentalities do not allow realistic, logical conclusions and action, and when, in many cases, prejudice and stereotypes, arrogance, or laxism and ignorance degenerate into blind fury and vendetta.
But when one witnesses affairs like:
https://en.wikipedia.org/wiki/Marc_Dutroux
http://www.dailymail.co.uk/news/article-398909/Paedophile-gets-20-years-worst-child-sex-abuse.html
one will wonder why incurable, recidivating pervert criminals should not be castrated and never be allowed to get out of prison again, all the more, when looking into news and statistics:
https://en.wikipedia.org/wiki/Rape_statistics
https://en.wikipedia.org/wiki/Prostitution_of_children
https://en.wikipedia.org/wiki/Human_trafficking
https://en.wikipedia.org/wiki/List_of_serial_killers_by_number_of_victims
But we cannot predict how familiar and less familiar people will evolve, and neither do we know if we can progress and improve ourselves.
And there is, though, always a risk that innocent people are falsely accused and sentenced in the place of the real culprits.
Did somebody read "The Franchise Affair"?
https://en.wikipedia.org/wiki/The_Franchise_Affair
Furthermore, in most of the cases, the victims have not their saying (if they survive) ...
We were taught not to act according to the "lex talionis" system and to forgive, so as to forgive oneself, but in such extreme cases, I think that forgiving might not go without making sure that such criminals cannot do further harm ...