I've read quite a few books and articles that elaborate on the issue of anger. I observed that intellectual approaches mostly hold resentment and avoidance towards it. "To be happy, to become a better person, you should rebuke all anger." That's the idea. On the other hand, most of the voices that embrace anger come mostly from anarchist and radical groups, terrorists and rebels, and religious sects.
There is no middle ground. There is no balance.
“It is wise to direct your anger towards problems -- not people; to focus your energies on answers -- not excuses.”
William Arthur Ward
There are certain issues in which anger towards them can and should be justified. When the weak are being opressed, when the innocent are being convicted, and the pure discriminated, that is a good direction to target your anger towards. Not the people. The issue. And yes, there is a difference. Because when your anger is unleashed on people, there is the tendency of resenting them and ultimately separating from them, without showing them of what they're doing is wrong. When you're mad directly at them you don't care about helping them one bit. You just want to hurt them. Now, on the other side of the coin, if you are angry towards an issue (human trafficking, war, abortion) you partner up to help those who are involved with the issue to show them its harmful and dark side. And yes, you can help people when you're angry. In fact, most rehab organizations that I am familiar with started by people who fell in the trap of drugs, their anger towards them is indescribable, and simply wanted to help others escape from their claws.
Anger can be good. I like to see it as a necessary evil. Powerful, yet unpredictable. Its motives questionable and risky, a dark angel, but if used wisely- and for the right reasons- can play a major impact in the process of making this world a better place.