The National Labor Relations Act (NLRA) provides that “Employees shall have the right . . . to engage in other concerted activities for the purpose of . . . other mutual aid or protection” In short, employers who are “union-free” are still prohibited from retaliating against or interfering with employees who engage in “other concerted activities” for their “mutual aid or protection.” The National Labor Relations Board has stepped up its activity in recent years in cases involving alleged violations of the NLRA in non-union workplaces.