Today in these United States, we have the highest percentage of the population in incarceration of any nation on this vast Earth, verifiably. Long tolerated police brutality has due to the collapse of the news censorship caused by the internet and social media become a popular issue- and a sore on the gums of race relations- seeing as African American males are often targeted for such brutality, as part of the wider phenomena of over-empowered police officers pursuing their own prejudices in the vacuum of checks and balances.
But the problem is not just prejudice: it's protocol. The hand-cuffs used to restrict accused citizens, who are presumed to be innocent under legitimate law, are so restrictive that the prisoner often cannot walk safely without police guidance- which points him to a claustrophobic back-seat of a police car where he then undertakes a rocky ride without a seat belt. All of this is in totality a near death experience, which greatly lessens the ability of the accused to resist plea deals and offer an organized legal defense, however innocent the citizen may be of the original crime.
All told, police brutality and mass incarceration are twin vices that cost the United States greatly in productivity and family cohesion, but perhaps most importantly are a taint upon legitimate law and order, which is needful.