If you want a calmer, more reflective treatment of the issue, I would recommend Radley Balko's book "Rise of the Warrior Cop: The Militarization of America's Police Forces".
Although it's pretty hard to discuss it calmly, precisely because once you start digging into it, there's so much stuff that's plainly damning and disgusting. For example, Balko also collected a significant number of quotes from law enforcement in his book; let me share some:
"Why serve an arrest warrant to some crack dealer with a .38? With full armor, the right shit, and training, you can kick ass and have fun."
"The officers with SWAT and dynamic-entry experience interviewed for this book say raids are orders of magnitude more intoxicating than anything else in police work. Ironically, many cops describe them with language usually used to describe the drugs the raids are conducted to confiscate. “Oh, it’s a huge rush,” Franklin says. “Those times when you do have to kick down a door, it’s just a big shot of adrenaline.” Downing agrees. “It’s a rush. And you have to be careful, because the raids themselves can be habit-forming.” Jamie Haase, a former special agent with Immigration and Customs Enforcement who went on multiple narcotics, money laundering, and human trafficking raids, says the thrill of the raid may factor into why narcotics cops just don’t consider less volatile means of serving search warrants. “The thing is, it’s so much safer to wait the suspect out,” he says. “Waiting people out is just so much better. You’ve done your investigation, so you know their routine. So you wait until the guy leaves, and you do a routine"
"One day, with a big smile on my face, I popped in to tell my deputy chief, Ed Davis, that I thought up an acronym for my special new unit. He was still, as we all were, glued to the classic concepts of policing, which discourage the formation of military-type units. But he realized some changes would have to be made. “It’s SWAT,” I said. “Oh, that’s pretty good. What’s it stand for?” “Special Weapons Attack Teams.” Davis blinked at me. “No.” There was no way, he said dismissively, he would ever use the word “attack.” I went out, crestfallen, but a moment later I was back. “Special Weapons and Tactics,” I said. “Okay?” “No problem. That’s fine,” Davis said. And that was how SWAT was born."