He was arrested by the police for loan sharking to desperate people.

loan sharking 是由 loan（贷款）和 shark（鲨鱼）组成的复合词。shark 在这里比喻"贪婪掠夺的人"。 loan sharking 指以极高利率放贷的非法行为，即"放高利贷"。这种借贷方式通常伴随着暴力催收等非法手段。