From Longman Dictionary of Contemporary Englishclamp down phrasal verbSTOP something THAT IS HAPPENINGto take firm action to stop a particular type of crime → clampdown on The police are clamping down on drink-driving offenders. → clamp→ See Verb table
Examples from the Corpus
clamp on• Police say the clampdown on drink-driving has been highly successful.• The new administration has promised a clampdown on corruption.• San Francisco cops are clamping down on a new brand of outlaws: sidewalk-hogging chess players.• The situation could worsen this year as the government continues to clamp down on credit.• The police are clamping down on drunk drivers.• She was determined that Marguerite would not suffer for it, and she clamped down on her growing fears.• Meanwhile, local police are clamping down on high-tech crime.• Recently the courts have clamped down on joy-riding.• Officials will be able to make key industry appointments and clamp down on manufacturers not making adequate profits.• The new, tougher laws are intended clamp down on the carrying of knives and other weapons.• New laws will clamp down on the illegal smuggling of cigarettes and tobacco.• Leaks from Clinton's team suggest Democrats may clamp down on the massive amounts executives can earn.• My father would clamp down on their education - their only means of freedom.• If we don't clamp down on these troublemakers now, the situation could get out of control.• Children's organizations are calling for a clamp-down on TV violence. 