At City Hall, Restaurants Vent Letter-Grade Gripes March 7, 2012, 4:43 pm Dozens of New York City restaurateurs filled City Hall on Wednesday afternoon to voice their frustrations with the city health department's new process of assigning letter grades for food safety. City Room reports that more than 300 people filled the chamber of the City Council, whose speaker, Christine C. Quinn, had called a hearing to respond to what she said was "a wave of complaints" from restaurant operators. Mayor Michael R. Bloomberg tried to get out in front of criticism on Tuesday by calling a news conference to declare the letter-grading a success, saying it had led to a decrease in airborne diseases like salmonella.