You're optimistic that these situations are rare? I agree that whatever the number of incidents like this that there are, they are sensationalized in the media, especially social media, and therefore are given a sense of increasing ubiquity. However, it seems more and more like something such as a simple traffic stop culminates with additional law enforcement vehicles responding and a foreboding potential for strong arm tactics if a citizen protests their treatment at the hands of often inflexible and surly attitudes of aggressive police officers. Additionally, if a bystander decides to offer additional protest for the rough and unnecessary treatment of friend or stranger , you know what will happen to them. I've seen it. I've been a witness to it. I've been involved in it.

There seems to be a great anxiety building over an increasingly militant style of over equipped and deadly forceful police departments, especially in urban areas. It doesn't take very much to light the fuse because society continues to regress into a crush of seeming helplessness. It is more than not a perception rather than a reality, but in the wash there isn't much difference in the two.
Have you ever seen a large blacked out SUV with 30 flashing lights on it at a simple traffic stop? I have. More and more it's common. I guess that's my point. The soft violence of perceived helplessness at the hands of aggressive law enforcement is feeding on itself.