In Apex Hosiery Co. v. Leader, 310 U.S. 469, 489, 60 S.Ct. 982, 989, 84 L.Ed. 1311 (1939), union members from nearby factories took over the plaintiff's plant and remained in possession for more than a month. Id. at 482, 60 S.Ct. at 985. The invaders changed the locks, wilfully wrecked machinery, and damaged property and equipment. Operations at the plant could not resume for two months after the plaintiff regained possession. Id. The union acted to force the plaintiff to hire only union employees. Id. at 482, 60 S.Ct. at 985. The Court explained that although the union members violated the civil and penal laws of Pennsylvania, if no antitrust violation occurred, the violence and state-law violations did not confer federal jurisdiction. Id. at 483-84, 60 S.Ct. at 986-87. The Court rejected the union's contention that all labor activities are exempt from Sherman Act, id. at 487, 60 S.Ct. at 988.