I think we try to show our anger who stay nearby us. We just find a mistakes or their activities which we don't like is enough to remove all the frustration. Besides we can't say against police, leader and government because we need to face the consequences if we do. So the safe way to express frustration is those people who stay nearby us. Sometimes the mistakes is ours but we don't think it as our mistakes and that's the problem..
Yeah... many of us will never admit that we're wrong, but we're quick to see others as wrong. And react as such. It's just annoying!!