There is no "December 12th Movement" as such, as opposed to one man, Robert "Sonny" Carson. Carson, a convicted kidnapper, has led criminal gangs in Brooklyn since the 1960s. In 1968, as part of the "community control" (read: apartheid) movement in Ocean Hill-Brownsville, his gang attacked white school teachers, and helped precipiate a series of teachers strikes.
During the 1970s, Carson spent a few years in prison. The 1980s saw him publicly demanding extortion money from Korean grocers whose stores had brought the first fresh produce that many black neighborhoods had seen in generations. When the grocers would not pay the extortion, he started -- with the help of New York City Mayor David N. Dinkins -- a violent "boycott" against two Korean groceries in Flatbush, Brooklyn.
Since the 1960s, Carson has worked continuously -- with black "educators" -- to run white teachers out of schools serving predominantly black children, and has even had his henchman brutally beat up black school administrators who refused to cede control of schools to Carson.
New York City's school officials response to Carson was to do ... nothing.
The teachers' union (United Federation of Teachers) response to Carson was to do ... nothing.
A series of prosecutors' response to Carson has been to do ... nothing.
A series of New York City mayors' response to Carson has been to do ... nothing. The exception to that rule was mayor David N. Dinkins, who helped Carson, by ordering the NYPD to violate a court order, which demanded that police keep Carson's thugs at least 100 feet away from the stores they were "boycotting." Until a second judge ordered Dinkins to comply, the mayor had ordered police to ignore constant death threats and assaults against the Korean grocers.