Our latest library borrow was "Kill the Irishman", a true story based on the life of Danny Greene. Green was a dock worker who became the union boss of the Cleveland longshoreman's union, battled the mafia to try and gain control of unions, and worked as an FBI informant to help bring down not only the mafia in Cleveland, but in four (or five?) other cities. Unfortunately, he had to die by car bombing in order for FBI to hunt down and capture the mafia guys responsible for his death. Once captured, they ending up singing like canaries and gave away all their compatriots.
I remember that movie, it was very good.