When the results of physical interaction are considered less important than the "purity of intent" of the practitioner, I get very very scared. This type of divorcing action from intent has led to some of the more unwholesome ethnic and religious cleansing in history, often in the name of what is "good" (ok, extreem case I know, but large errors start small).
I agree, good practitioners of any martial art can mitigate the level of violence they use and this is an ethical decision where intent matters. However, the results of any martial art technique used are violent to a greater or lesser degree. If your intent was truely non-violent, you would never use any MA technique, no matter what the provocation. Instead, as has been intimated in previous posts, the techniques are just a part of the philosophical training and effectively "not for use" in a wider context.