In 1920 around Matewan, West Virginia, the coal miners tried to unionize and the coal companies brought in the Baldwin-Felts Detective Agency to crack down. Police Chief Sid Hatfield sided with the miners, deputized all the men in town, told them to go home and get their guns and confronted the detectives, telling them they had no legal authority.
In the climactic shootout, known as the Matewan Massacre or Battle of Matewan, on the town side the mayor and two miners (one who confronted the detectives and one unarmed bystander) were killed with four wounded, and seven of the Baldwin-Felts detectives (including Albert and Lee Felts) were killed, and one detective wounded.
Sid Hatfield, who may or may not have been related to the notorious feud clan, has become a folk hero of sorts. He was known to carry a pair of Smith & Wesson .44 Hand Ejector revolvers from newsreels at the time. I believe they used Colt DA revolvers in the movie "Matewan".
The movie brings up, among other questions, at what point, when justice is denied through all other channels, are people justified in taking up arms?
The movie in a closing narration mentions that when Sid Hatfield was set to stand trial, several Baldwin-Felts detectives ambushed Hatfield on the McDowell County Courthouse steps (in accordance to courthouse rules, Hatfield left his guns at home). That ambush led to the Battle of Blair Mountain.
On the movie: http://en.wikipedia.org/wiki/Matewan
On the massacre: http://en.wikipedia.org/wiki/Battle_of_Matewan
From the Logan Coal Operators Association, a different point of view: http://www.wvculture.org/history/labor/matewan04.html