Run a search on "Florida East Coast strike" in the early Sixties, and you'll read about trains being blown off the tracks by union members, with their bosses piously blaming the railroad for the violence.
There was a labor confernce recently where SEIU crashed the gate and attacked the attendees. People were injured and one person suffered a heart attack. And this was against their “union bretheran”! The local county home care workers held an election here in Fresno to decide if SEIU or a breakaway union would reperesent the workers. There were accusations of intimidation and threats of violence made by SEIU against workers.