witch-hunt
n
(a) search to find and destroy people thought to be witches 搜捕女巫.
(b) (fig usu derog 比喻, 通常作贬义) investigation made in order to persecute people who hold unorthodox or unpopular views 为迫害持非正统观点者而进行的调查
The crusade for sexual morality is turning into a witch-hunt. 捍卫性道德的运动正在转化成对持异议人士的迫害.