Mr Glover filed a formal complaint of racial bias after three taxis turned him down in Harlem last week, and a fourth driver picked him up only with reluctance.
In measures announced on Thursday, Mr Giuliani said that cabbies who are reported passing by a black would-be customer would have their licences suspended pending a hearing and their cabs impounded. Those convicted could lose their licences for good.
While few denied that there were cases of discrimination, the reaction from cabbies was mixed. "Your licence or your life" was how some drivers saw the new crackdown. Others said that the business was now so competitive that they had to pick up everyone: "We're just trying to make a living, after all."
Others accused Mr Giuliani, who is expected to run for the Senate against the First Lady, Hillary Clinton, of brazen politicking. "he's just doing it for politics," said one. "Let him drive a yellow cab for a day."