The U.S. Court of Appeals for the Fifth Circuit upheld an NLRB ruling that said In-N-Out Burger was not allowed to ban employees from wearing small pins that read “Fight for $15”. The California-based burger chain requires its employees to follow a detailed dress code that prohibits any kind of pins and stickers. The NLRB’s general counsel found this rule to be in violation of federal labor law. On appeal, an administrative law judge rejected the company’s argument that their interest in maintaining a unique brand image and concern for food and safety qualified as “special circumstances”.
See "In-N-Out Burger Can't Ban Workers' 'Fight for $15' Pins, Fifth Circuit Rules", John Council, Law.com, July 9, 2018