It's bad, but from outsiders looking in, I can't help but think that they may believe that there's a daily war zone occurring in the US, on the level of Syria and Iraq, and that it isn't safe to go outside (yeah, that's an absurd notion, but some of EuroGAF believe this. They use that as a reason to avoid visiting the US). Nothing like that. But I stress, that isn't to discount the seriousness of the frequent cases of police brutality towards civilians. Many police officers have been abusing their authority and covering up for each other to avoid punishment.
One particular incident involving a younger guy getting gunned down by a cop still infuriates me. The police received calls from "concerned witnesses" that there were a group of guys walking around town, and the "concerned" part basically boiled down to these guys wearing baggy clothing and baseball caps. They fit the thug stereotype, I guess. So naturally, that means that they are gang bangers and out to commit theft and murder. They were coming out of a convenience store, and the cop was calling out to them. One of the guys had headphones on and couldn't hear him, so he most likely put his hand in his pocket to turn down the volume, and the trigger-happy cop shot him. Senseless murder.