crackdown (on somebody/something)severe action taken to limit the activities of criminals or of people opposed to the government or somebody in authority严厉的打击；镇压
a military crackdown on student protesters对抗议的学生实行的军事镇压
a crackdown on crime对犯罪的严厉打击
The government has ordered a crackdown on truancy.政府已经命令严厉查处玩忽职守行为。
They’re having a crackdown on private phone calls from the office.他们正在严厉查处在办公室打私人电话的行为。