Where do you put righteous indignation, as self defense or as revenge?
I'd say neither. Righteous indignation is a natural response to some situations as a brief and passing thing -- but if you fan the fire and build it up, as we so often do, it's unhealthy self-indulgence. Yes, the situation is wrong. Yes, you're justifiably upset about it. But as soon as you realize that, it's time to acknowledge it and set it aside, rather than continue to validate and build up your sense of yourself as the aggrieved party. The offense, whatever it was, doesn't become any worse if you dwell on it; all that you do is blow the whole thing out of proportion in your own mind, and diminish your own capacity to make a measured and proportionate response.