Out of the 800,000 LEO in the US, we're surprised to see a few hundred YouTube videos? We only see the bad because that is what gets the majority of people in an uproar. Post a good video of a LEO and people will be "Ok!" or "Good job," and the thread dies in 2 pages. Post something like the topical video, and you'll get three weeks and 20 pages of "Cops are evil!" and various epithets.
For my personal opinion on the video, the cop's actions were overboard for the situation. A guy was just beaten and home violated. Sure, I'd be ticked off too, and the LEO should be cognizant of that. The victim acted immaturely, but that doesn't allow the officer to act the way he did. As much as the victim seems to be someone not to be my friend, I think he does have grounds for police brutality and unlawful detaining.
All LEO should watch the YouTube video of the trooper who gave an old guy a speeding ticket and the guy flipped out. The trooper stood there and took it. Then, when the old guy tore up the ticket and threw it out the window, the trooper told him "If you don't pick that up, I'm going to cite you for littering."
Anecdotal, I have two friends who are LEOs, and are very down to earth, family men, and in my experience, good guys. Just like painting all gun owners with the same brush is bad, so is painting LEOs.