Viewers were left upset and fuming after watching Reggie Yates' investigation into gun crime in Chicago.
Many were horrified to hear that the murder rate in the Windy City is soaring, with a large percentage of the victims being young African-American men.
But it was the scenes and tales of police brutality that really riled people.
Many said they were "repulsed" or "disgusted" after seeing and hearing about police violence.
There wasn't a bad review of the documentary to be seen on Twitter.
And Reggie himself won plenty of praise.
Most viewers seemed to conclude that gun culture was ruining America, and many Twitter users added the hashtag #putthegunsdown.