Actually, if you ever put your bias aside and watched any of the videos, you'd see a lot of them are not retaliation. It's the cop asserting his authoritah. How could a woman who is handcuffed and face down on the floor even elbow someone? How can a guy walking down the street do anything to a cop before he gets slammed by an open truck door? What does a guy do that deserves having he neck knelt on for 9 minutes? That's why cops get fired and charged.
You don't have to use your imagination, just watch the videos. The things bodycams catch make most people wonder what the cops were getting away with in the days of Rodney King and 'Straight outta Compton'. I don't for a second think police are acting out of malice, but I think a few of them are bullies and the others supposed good ones cover up those incidents out of some sort of messed up 'esprit de corp'. That is how they choose to 'Protect and Serve'.
All you have to do is watch the video footage of a cop stopping a blind guy for having a cane folded in his back pocket, and the encounter escalating to a beat down to know that the police have been trained in the art of escalation and have it down to a science.
Or this wonderful encounter:
us-politics-f18/usa-police-misconduct-reports-t109913-2295.html#p2426769Watch it, don't watch it. All you can do is become informed. You should even look at some of the video about the Calgary Police Service. Lots of cowboys there.