Here's a video that was taken in St. Paul, Minnesota, in January of 2014. It shows a black man being arrested because he waited in a public place, a skyway, for his children to get out of school. Someone had called the police to complain that there was a black man in the skyway, and the police responded, as if it were an actual emergency. Then, after finding no crime in progress, they took the man to jail, leaving his children with no one to take them home. The person who attempted to record the whole incident was forced to reclaim his cell phone, by the way. It was unlawfully confiscated. Here's the ACLU guide for snapping pictures and video in public places.
To those who really don't understand why there were riots in Ferguson, Missouri because of Michael Brown's death, or why is it important to hold police officers in Baltimore, Maryland accountable for the death of Freddie Gray, just remember that digital photography has become the great equalizer.