Question: The Truck Drivers' Union was engaged in a primary labor dispute with Piggyback Services, Inc., a nonunion employer. The dispute began when the Santa Fe Railroad awarded Piggyback a subcontract to ramp and deramp intermodal freight (freight carried inside trailers and containers on railroad flatcars) at Santa Fe's Richmond, California, rail terminal. That work had been performed by union members for a wholly owned subsidiary of Santa Fe. Piggyback had initially agreed to hire the former union workers, but later reneged on that promise, and the union began picketing and distributing handbills at Santa Fe's Richmond rail terminal. In an effort to insulate itself from the union's labor dispute with Piggyback, Santa Fe designated a gate, Gate 1, as the sole entrance to the Richmond facility for employees, customers, visitors, and suppliers of Piggyback. Santa Fe also posted signs at four other entrances to the Richmond facility, designated as Gate 2, Gate 3, Gate 4, and Gate 5, stating that these "neutral" gates were reserved for the exclusive use of Santa Fe's employees, customers, visitors, and suppliers, and that Gate 1 was available only for Piggyback's employees, customers, visitors, and suppliers.

Although Piggyback employees entered only through Gate 1, and the union fully acknowledged that it had no labor dispute with Santa Fe, the union began picketing at the four neutral gates. Handbills distributed by the union at neutral locations urged neutral employees and customers entering the Santa Fe railway yard to either honor the picket line or, alternatively, to cease all work related to Piggyback's day-to-day operations. The union sent letters to the presidents of the seven unions that represented Santa Fe employees. The letters requested that union members employed by Santa Fe not perform work directly related to Piggyback's operations at the Richmond terminal. A similar letter was sent by the union to United Parcel Services (UPS), Santa Fe's primary unionized intermodal trucking customer. The UPS drivers and other Santa Fe customers honored the picket line by refusing to deliver intermodal freight to the Richmond terminal. In response, Santa Fe established a drop-off site about a mile-and-a-half from Gate 3 for use by UPS and other Santa Fe customers. Although no Piggyback employees were stationed at the UPS drop-off site, the union expanded its activity to that location. The union also picketed at the two railroad spur lines where intermodal freight cars entered the railway yard. Santa Fe filed an unfair labor practice complaint with the NLRB, alleging that the union picketing violated Section 8(b)(4). How should the NLRB rule on the complaint? Why? Explain your answer. See NLRB v. General Truck Drivers, Warehousemen, Helpers and Automotive Employees of Contra Costa County, Local No. 315 [20 F.3d 1017 (9thCir. 1994)].