New York City police officers are protesting by refusing to work. It's not the first time.

New York City's police officers are rebelling publicly against Mayor Bill de Blasio, who drew particular attention in recent weeks when he acknowledged that he taught his biracial son to be careful around police simply because of his race.

"What parents have done for decades, who have children of color, especially young men of color, is train them to be very careful when they have a connection with a police officer, when they have an encounter with a police officer," de Blasio told ABC News' This Week. "It's different for a white child. That's just the reality in this country."

(Read more: Why police unions protect the worst cops.)

Police took de Blasio's comments personally. Following the December 20 shooting of two New York City police officers, Patrick Lynch, president of the NYPD union Patrolmen's Benevolent Association, said there was "blood on the hands" of the mayor.

"It's different for a white child. That's just the reality in this country."

Several days later, police officers turned their backs on de Blasio as he spoke at a funeral for one of the slain officers. Then, during a December 29 speech for an NYPD graduation ceremony, members of the crowd booed de Blasio multiple times. And according to the New York Post, police are now working as little as possible — arrests are down 66 percent for the week of December 22, compared to the same time last year — in open protest of de Blasio's administration.

This revolt comes at a time when racial disparities in police use of force and the criminal justice system are getting a lot of attention. As protesters march around the country over the killings of Michael Brown in Ferguson, Missouri, Eric Garner in New York City, and other black men who have been killed by police, cops are reportedly feeling more and more under attack.

But this kind of tension between police, the public, and civilian leaders isn't a new phenomenon. In the 1960s, similar tensions played out when black Americans around the country marched and even rioted against what many at the time viewed as a racist, corrupt criminal justice system. Police responded to the criticisms with the same kind of rhetoric they are using today — sometimes telling elected leaders, including in New York City, that they will not work if they're criticized.

I talked to Heather Ann Thompson, a Temple University historian who has extensively studied urban policing issues, about these conflicts. Here's what she had to say.

Police officers revolted against civilian leaders during previous periods of racial unrest

NYPD graduates salute as Mayor Bill de Blasio speaks. (Andrew Burton / Getty Images News)

"Before the rebellions in [the 1960s], there were lots of black leaders, middle-class leaders, and working-class leaders telling the mayor, 'You have to do something about your police department,'" Thompson said. "In Detroit, the mayor, Jerome Cavanagh, was a liberal mayor who was elected, like de Blasio, on the heels of a more conservative, law-and-order mayor. He took that charge seriously — like de Blasio, trying to get rid of egregious police practices. But the black community felt the police were just unreceptive to it."

"The police don't like it when the mayor starts talking about things like civilian review of police activity or censuring police abuses of the black community, because they feel like they're being betrayed by city hall," she added. "The broader history of police departments being very hostile to mayors trying to reign them in is not new. When Detroit Mayor Jerome Cavanagh tried to root out police brutality by appointing George Edwards as a police commissioner in 1962 … the guy quit. He basically said, 'This department is so bigoted that I can't make any inroads.'"

But police leaders' rhetoric seems more aggressive this time around

"It's much more vocal and it's much more aggressive than things we've seen before," Thompson said. "I think de Blasio touched a nerve in a way that other city mayors haven't — in no small part because he made the statement about his own concern in raising a biracial son in New York."

Cops' protests in some ways seek to undermine civilian rule of police

Pictures of two slain NYPD officers are displayed during a graduation ceremony. (Kevin Mazur / Getty Images News)

"From the police point of view, they are working a very, very dangerous job," Thompson said. "In that respect, they feel like they're taking on the greater risk of bringing safety to the city and that their judgment should be respected. They feel they know best on the ground what needs to happen and they deal with problems on a direct basis more than any bureaucrat at city hall does."

"Rather than being a union in a traditional sense, [police union members] see themselves as a much more of a fraternity or a brotherhood," she added. "So when they get criticized, they close ranks."

Work slowdowns and stoppages were previously tried by police

"In 1967 in Detroit, there was a massive 'blue flu,' they called it, in which police protested by basically not showing up and not doing the job," Thompson said. "That method of protesting is saying, 'Screw you. We're not going to do our jobs. We're not going to arrest people. We're not going to police. Let's see what happens now.'"

But these kind of protests can backfire by exposing unnecessary arrests

"The fact of the matter is that so many of the arrests are just gratuitous — they're harassing people on the ground. It's what led to so much of this anger [from the black community] to start with," Thompson said. "Everyone took a different reaction from looking at the Eric Garner video. But one of the things that struck me is he says at the beginning of the video, 'Every time you see me, you want to harass me.' 'Please leave me alone,' he keeps saying. That's really the point: this low-level riding up on people, slamming them against car doors, and busting in their houses make black communities in every city in America feel like they're living under siege."

Previous reforms were undone over time

The scene of Eric Garner's funeral. (Getty Images News)

"The rebellions of 1960s had really concrete and immediate effects on the way policing happened," Thompson said. "This is why we get, for example, Miranda rights… By the 1960s, there were much stronger civilian review boards of police. We got residence requirements, so police have to live in the city in which they police."

"But in the last 40 years, we have had a counter-revolution — there's no other way to put it — against every bit of that stuff I just mentioned," she added. "Prisoners used to be able to use the courts to sue when they were being abused, but then we got the Prison Litigation Reform Act that makes it almost impossible for prisoners to sue on their own behalf. We have Miranda rights, but now many officers, including private security teams, are not obligated to use Miranda rights because they're private. We have civilian review boards of police, but they have pretty much been gutted in many cities; they don't have a lot of power. We have residence requirements in cities like Detroit that were gotten rid of — you don't have to live in the city now to police."

At the root of racial disparities is too much criminalization

"It's going to take generations for my children's children to undo what it's meant to have a 40-year war on drugs and crime where only black people are targeted for what they do and white people aren't," Thompson said. "That changes the way generations of people understand race. It makes it seem that blackness and brownness is associated with criminality."

This interview was edited for length and clarity.

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