In Griffin et al. v. Maryland, the U.S. Supreme Court ruled that a state cannot use its trespassing laws to discriminate against African Americans in public places or facilities operated by private entities but open to the general public. The case involved several black and white protesters who were arrested for trespassing at an amusement park in Baltimore County, Maryland after they refused to leave due to their opposition of the park's segregation policy. They argued that their arrests violated their constitutional rights under the Fourteenth Amendment’s Equal Protection Clause because they were based on racial discrimination. The court agreed with them and held that when a state enforces such discriminatory policies through its criminal trespass laws, it becomes complicit in violating citizens' equal protection rights even if those policies are implemented by privately owned establishments like amusement parks or restaurants rather than directly by government agencies themselves.

In the dissenting opinion for Griffin et al. v. Maryland, Justice Harlan argued that the majority's decision to reverse convictions based on state action was misguided and overly broad in its interpretation of the Fourteenth Amendment. He contended that not all actions by private individuals should be considered as state action just because they are performed under some form of legal authority granted by a State. In this case, he believed that it was wrong to consider an amusement park's racially discriminatory policy as a state action simply because it had been enforced by an off-duty police officer employed privately by the park itself. The justice felt there needed to be clearer boundaries between what constituted private prejudice and actual discrimination sponsored or encouraged directly by a State.