You have a terrible habit of reading things where I haven't wrote them; where do I say that I condone the actions of the police in that video? Clearly, I discuss the police as an establishment in my post, and, as said, there are consequences for police who act incorrectly (just repeating 'shame no-one persecutes the cops', without evidence to support your claim, is both inane and inaccurate). I'd also like to point out, you say the neighbours called the cops, yet you put all the blame on the police. If it was just some drive-by on the cops part I'd be more inclined to agree with you, but, again, it sounds like they were just following orders.
When people are saying you need a reality check they are in no way suggesting you're too moral act intelligently ('my heart is too big' or whatever), in fact its quite the reverse; you have a child's understanding of morality, where people are good or people are bad. People are people, and they're damn near all plagued by some unfortunate circumstance or another. And when you get out of your parent's house, get a job, and have a few people that you yourself are responsible for, then you'll see that 'society' is greatly illusionary and that it is still a dog-eat-dog world.
Also, the whole gun in crowded area thing was just an example; but what I wrote earlier still applies. You have to remember that most of the police's day-to-day dutes are 'keeping the (so-called) peace'; in turn this means intervening in domestic disputes, quieting the drunk, because they are disturbing the neighbours, interrupting a drug deal, because its a drug deal. They can't be waiting for a court order for these flash in the pan, and largely trivial, occurences, regardless of if these things take place behind closed doors. However, what they cant do is harass someone for being x ethnicity in a 'nice neighbourhood', nor can they go "Well, he's x ethnciity, so he must have stolen that car". That kinda stuff is what costs them jobs, and they would probly only risk it if their higher-ups are breathng down their necks for 'accomplishing nothing' (ie. no arrests) for the last three months or whatever, meaning they are likely to lose their jobs anyway. So I reiterate, don't hate the player, hate the game.