Violent punishments are necessary for punishing all kinds of criminals. This way, these criminal scumbags will be filled with fear, the kind of fear that prevents them from committing a crime. Simply putting someone in prison does not seem to work nowadays in the Western World. People should know discipline.
NO, I'm NOT excusing torture or cruel and unusual punishments. I'm NOT defending extreme violence. What I mean is for instance,
Take an example of a non-violent crime that nevertheless has a victim. Financial fraud. No violence is used but there is still a victim. This crime has to be deterred somehow. One option is prison, and in the most egregious cases of financial fraud it's the best option (if anything financial fraud doesn't receive prison time often enough) Prison is a form of violence. If the convict refuses to go quietly he will be transported there by force. Even if the courts decide to be lenient and sentence the convict to fines and community service prison still remains a possibility if he doesn't comply with that sentence.
But while some violence is necessary to uphold law and order there is a difference between necessary violence and extreme violence. It would not be appropriate to sentence a financial fraudster (or anyone for that matter) to waterboarding.