“The confidential informant infiltrated a NAN meeting on May 3, 2008, and reported back to the NYPD's Intelligence Division,” Levitt wrote. “…According to the police document, the informant, who was identified not by name but by a five-digit number given to him by the department, provided the NYPD with a detailed description of NAN's protest plans, including the names of prominent African-Americans set to participate, the locations where protesters would gather and the number of demonstrators who would offer themselves up for arrest.”

Since Levitt’s article was published, Black leaders have rallied behind Sharpton. Many said the situation bears shades of the FBI’s Counter Intelligence Program, called COINTELPRO, that was initiated by then-FBI Director J. Edgar Hoover. From 1956 through 1971, the agency spied on Black leaders and tried to undermine civil rights and Black activism.

“This challenges our most fundamental rights and ignites memories of the Gestapo tactics employed against Dr Martin Luther King Jr. by the police authorities during a sad moment in American history,” said the Rev. Dr. W. Franklyn Richardson, chairman of the board, CNBC (Conference of National Black Churches) in a statement. “In too many instances the NYPD appears to be an obstruction to individual liberty and justice. They have crossed the line here and must be held accountable.”

In light of reports that the NYPD spied on members of the Muslim community and on Occupy Wall Street, this news further undermines the public’s trust in the police department, added entertainment mogul Russell Simmons. “It is troubling to think that those who are ordered to protect us are in fact working against us,” he said.

NAN and other Black leaders are demanding that N.Y. Police Commissioner Raymond Kelly investigate the allegations and offer a public explanation.

“Given the serious nature of the allegations and the history out of which they arise, there is no acceptable response but for the city and the police department to show us all their cards. Our community must be certain that the people we count on to enforce the law are not breaking it,” said NAACP President and CEO Benjamin Jealous.

Added the Rev. Jesse Jackson: “…Police Commissioner Kelly, as he promised over a year ago, must issue a full fact-finding report on the matter, fully disclose the spying activities of the police department and make restitution to Rev. Sharpton and NAN for this invasion of privacy.”

Meanwhile, NAN is considering the best response, said attorney Michael Hardy, NAN’s general counsel and executive vice president. “We are weighing all legal options, including whether there was a violation of federal consent decrees.”