寻瑕伺隙

Explanation: Search; flaw in the jade spots, metaphor shortcomings; any observed gap loopholes and opportunities. Find someone else shortcomings, to see if there are loopholes. Refers to the aggressive stand. 　　Source: Lu Xun's "two books" Sijiu students had played against the president of trend, and although calm, and often angrily, each finding flaws Sixi, and things were difficult. " 　　Examples: The students had played against the president of trend, and although calm, and often angrily, for every ~, and the work were difficult. (Lu Xun, "two books" Sijiu)