In a case of first impression, the National Labor Relations Board has ruled that a union protest urging a boycott of a business with which the union does not have a direct labor dispute—known as a secondary boycott—does not constitute an unfair labor practice when done solely with banners and leafleting outside the business. The ruling clearly will make it harder for a neutral employer to act when a union denounces its business relationships and pressures the public to stop patronizing it in an effort to force the employer to cease doing business with employers feuding with the union.

In United Brotherhood of Carpenters and Joiners of America, 335 NLRB 159 (2010), the union had been involved in primary labor disputes with several construction contractors. To further its position, the union picketed several businesses, including a hospital and a restaurant, that hired the nonunion contractors. Members placed banners, 16 feet long and 4 feet high, on sidewalks outside the businesses and handed out leaflets.

The secondary businesses and one primary business filed unfair labor practice charges. The Board, however, found the protests did not violate the National Labor Relations Act, relying on the fact that the signs were stationary and positioned a sufficient distance from business entrances. It also emphasized that for bannering to be transformed into unlawful picketing, there had to be some verbal or physical confrontation.

Two board members strongly dissented, arguing that the decision "invites a dramatic increase in secondary boycott activity." The dissent also noted that the decision makes it unclear as to what proof an employer needs to stop a union protest.

Such uncertainty, paired with a likely increase in secondary boycotts, makes it crucial that businesses understand their rights and the limits of union protests.