天下乌鸦一般黑

Explanation: Metaphor is a matter of local exploiters and oppressors are the same bad. 　　Usage: Predicate; as object clause; with derogatory 　　Source: Yang Mo "Song of Youth" the first chapter: "天下乌鸦一般黑, here the dark, dirty, is not the same as elsewhere." 　　Examples: It also had quite a few days ago rumors, as I was in Beijing last summer, like, haha, really ~ zai. (Lu Xun's "Letters To Sun Fuyuan")