One of the trends of the last century is the de-linking of morality and magic. Crowley of course was the biggest and most viable leader in this, but there were many others from Spare to Dadaji as well as many others. This was a necessary phase for magic to undergo because by the turn of the century the concept of proper moral behavior was tied to many practices that were harmful (civilizing "savage" cultures, child labor, etc), hateful (racism, misogyny, homophobia, etc), and in some cases not really about ethics at all (Forced closures on Sunday etc.)
I mention all this because one of the formspring questions that I did not answer started out by praising me as someone who sees that there is no link between magic and morality, and for essentially being a "shoot first and ask questions later type of guy. Although this person was praising me, that is not praise that I want because nothing could be further from the truth.
It is true that when I teach protection magic or combat magic I do get into the subject of cursing. I even have my own ritual: "Inominandum's Shock and Awe Fuck Your Shit Up to Death Curse". I have not however actually used the ritual. I invented it as a teaching exercise. I feel that deliberately not covering cursing and harmful sorcery damages the tradition of magic overall and ill prepares people for what they may encounter in real life.
The part of the classes that everyone seems to miss however is when I say that there is almost always a better way. I try never to jump to harmful magic when I can avoid it. Even if someone or something is deliberately attacking me, I rarely attack back, preferring to let defense be my offense. In fact I usually try to make supplicating offerings on behalf of the person or spirit in question, that they let go of their anger. I also sometimes try to rein back some of the protectors that surround me because honestly, they can over react a little. I have regretted overzealous protection magic more than once.
I have used jinxes to confuse or dominate people in the course of business dealings where not doing so would cause greater harm. In a few cases I even did so just because I wanted my side to win and theirs to loose. These were not morally clean actions however and I would not pretend that they were.
The truth is that I do see a link between magic and morality. Compassion, truth, love, kindness, etc are all natural products of understanding and gnosis. Hatred, Violence, Lying, Theft, Selfishness, etc are products of ignorance. While in a state of pure contemplation it is true that actions have no Karma, however, most of us are not existing in that state all the time. One set of actions drives us towards realization, the other set away from it. I have seen this happen over and over.
Yes, you can draw power from negative emotions to fuel magic, but it is nothing compared to the power that you can effortlessly produce by cutting through those emotions and understanding the basis of reality itself.