The phrase "crack down upon" is correct and usable in written English.
Generally speaking, the phrase is used to mean enforcing rules or laws firmly. For example, "The government has decided to crack down upon companies that have been violating environmental regulations."
"We will step up actions to crack down upon terrorist groups and extremist organizations and track the wanted," said Yu Zhengsheng, the Chinese leader in charge of ethnic and religious affairs, Xinhua reported.
"We will step up the actions to crack down upon terrorist groups and extremist organisations and track the wanted," Mr Yu added.
In accordance with the government's interpretation of social assistance programs, a mandatory welfare-to-work program was instituted in the province along with a diligent crack down upon any perceived systematic or individual fraud.
Sometimes religious groups are tolerated or benefit from the authorities' benign neglect, but there have also been times when they were seen as a rival centre of power and cracked down upon, just as the Falun Gong sect has been hounded in China.The shadow cast by China looms large.
"Any act of anti-Semitism, no matter what the pretext, will be extremely firmly pursued and cracked down upon by the justice system," he declared from the steps of his Hôtel Matignon offices this evening after a meeting with Jewish community leaders.
"The Canadian mining industry has made significant efforts over the past while as an industry, but there are still a few actors that need to be, you know, cracked down upon and addressed more directly," Trudeau said.
And crack down the government has.
Occasionally, local officials try to crack down.
But it too is fading as governments crack down.
Police would always crack down.
