眼中钉 — “A nail in one's eye”

During the Five Dynasties period, Zhao Zaili served as a jiedushi (military governor) of Songzhou (present-day Shangqiu, Henan). He was corrupt and oppressed the common people, who hated him deeply. When he was dismissed from his post, the people of Songzhou rejoiced, saying, "It's as if a nail has been pulled from our eyes! How happy we are!" Unexpectedly, he was soon reinstated. Bearing a grudge, he imposed a tax of a thousand coins on every person in his jurisdiction, calling it the 'nail-pulling tax,' plunging the people of Songzhou back into hardship.

Another story from the Tang Dynasty involves Zhang Hongjing, the jiedushi of Youzhou, who was lax in discipline. His subordinates, Wei Yong and Zhang Zonghou, mistreated soldiers and were heavy drinkers, often carousing until midnight. When returning, they would precede with a large entourage, verbally abusing and driving away pedestrians. If they were displeased, they would scold soldiers as 'rebels.' Once, Wei Yong humiliated soldiers by saying, "Now that the world is peaceful, it's better to know the character '丁' (ding) than to be able to draw a two-stone hard bow." Later, when the imperial court sent one million strings of cash to reward the soldiers, Zhang Hongjing embezzled two hundred thousand, distributing only eight hundred thousand. Eventually, the soldiers and common people united, killed Wei Yong and Zhang Zonghou, and placed Zhang Hongjing under house arrest.