tighten the screws on
tighten the screws on somebody/somethingalso put the screws on somebody/something
to make it harder for someone to do something Government agencies need to tighten the screws on illegal immigrants. We are putting the screws on that country to end its history of helping terrorists.
Usage notes: sometimes used in the form put the screws to someone or something: The owners could really put the screws to the players.