An overview of the standards federal district courts in each federal circuit apply when considering whether to enjoin strike activity alleged to violate a collective bargaining agreement (CBA). In Boys Markets, Inc. v. Retail Clerks Union, Local 770, the US Supreme Court interpreted Section 301 of the Labor Management Relations Act (LMRA), which confers jurisdiction on courts to decide breach of CBA lawsuits, and created an exception to the anti-injunction provisions of the Norris-LaGuardia Act (NLA).