A crackdown is when the police, a school, a company, or a government suddenly starts treating a problem much more strictly than before. They do not just warn people; they hunt the thing down and punish it. You nearly always hear what the crackdown is aimed at: a crackdown on drugs, on drunk driving, on tax cheating, on street protests. News writers love the word, so it can sound bigger than the facts. Sometimes a few extra checks at the station get called a crackdown; sometimes it really is a wide, hard campaign with arrests. It is a noun for the action as a whole, not for one punch or one fine. In everyday talk people more often say they are being much stricter now; crackdown belongs more to headlines and serious reports. Though actually, once the word is in the air, people on both sides use it: officials like it because it sounds strong and in control, and critics use it when they want to say the state is coming down too hard.