To crack down on is to start dealing with something far more strictly. Crack down on speeding.
It describes a change in enforcement rather than in the law itself. Governments crack down on things that were already illegal and had simply been ignored.
1phrasecrack down onTo start dealing with something far more strictly.
“The council decided to crack down on parking outside the school.”
crack down on is a phrase.
Practised in Phrasal Verbs