In Timken Roller Bearing Co. v. NLRB, 325 F.2d 746 (6th Cir. 1963), cert. denied, 376 U.S. 971, 84 S.Ct. 1135, 12 L.Ed.2d 85 (1964), the court considered a union request for information concerning five grievances that awaited hearings before a chosen arbitrator.
In NLRB v. Swain Morris Construction Co., 431 F.2d 861 (9th Cir. 1970), this court assumed, without deciding, that an employee's refusal to cross a picket line at an employer other than his own is protected activity.