I think it is that there are other “units” just like the one in Memphis all over the United States, that state-sanctioned violence against civilians via a progressively armed police seems dystopian, and that a person can wind up dead from a traffic stop. Sure, these cops were arrested, but the ability for them to do what they have done in the first place is what the problem is. Edit: also, if it weren’t for similar protests in the past over similar events then these 5 cops might have gotten away with murder. National public outcry at these things helps ensure justice is found.