Skateboarding and Cops

Many people know about the age long rivalry between skaters and cops, but why does it exist? I'm not completely sure but I'll do my best to figure it out in this blog. I think it started in the 70's because of the skaters such as those in "Lord's of Dogtown", who were generally unlawful and harbored resentment for authority figures. And it's totally understandable that the police would take a disliking to this breed of skater. But as time progresses, their resentment still exists, and although some skateboarders are unlawful, most are not. And it's unfair that cops pick on us all the time when a lot of us really don't deserve it.
Their are so many police brutality videos when their are police officers that unnecessarily single out skateboarders. There's one titled "Go Skateboarding Day". Even before the video starts there's a picture of a cop on top of a 12 year old kid who was just skating on the street, choking him. At this point I guess the cameras catch up and the aforementioned kid is in handcuffs. The officer then tries to grab everyone watching that has a board. He ends up tackling a girl, arresting her, and two other guys when they weren't resisting.
The most frequent opening line for the cops/ person kicking you out is always "does this look like a skate park to you?" Well obviously it isn't a skate park if we are getting kicked out. Unfortunately most people live like 6 miles from a local skate park so were else are we supposed to skate? In every video I've seen it's always been the cops that start it, or at least throw the first punch. The typical setting for these ugly conflicts is there's a few people skating, obviously a person filming, in a place they aren't really supposed to. Then a rent-a-cop shows up, since he thinks he is the law, he starts hassling the skaters they get in a fist fight and then one of them backs down (usually the cop). This unnecessary resentment is probably what keeps it going on both sides. Skaters don't like cops because cops don't like skaters and vice-versa. It's a vicious circle that doesn't make anyone happy. I don't know what can be done to end it. There are some nice police officers, but there definitely aren't enough.