hysteria - A state of extreme excitement, fear or anger in which a person, or a group of people, loses control of their emotions and starts to cry, laugh, etc.

There was almost mass hysteria when the band played their final song and some in the crowd rushed towards the stage.
reprehensible - Describing behavior, actions, or conduct that is morally wrong and worthy of disapproval or condemnation.

Though he told people not to repeat it, it was reprehensible for him to spread rumors about his colleague, knowing it would damage her reputation.