Confucius on not trusting the throng

The master said, "When the mob hates someone, you must examine this. When the mob loves someone, you must examine this."

--Confucius (孔子) (551-479 BC), Analects of Confucius, (論語) book 15, ch 27

子曰、眾惡之、必察焉、眾好之、必察焉。