By now we are all aware of the threats made by right wing activist Scott Oskay.
The template for a violent encounter between armed right wingers and other demonstrators already exists. On November 3, 1979 a caravan of Klansmen and American Nazis ambushed a peaceful demonstration. Several of the demonstrators were activists trying to encourage the formation of a textile workers union among African American textile workers in Greensboro, North Carolina, but on this occasion the demonstration was an anti-Klan rally with the theme "Death to the Klan." Five demonstrators were killed and ten were wounded.
The incident became known as the Greensboro Massacre.