The San Diego free speech fight in San Diego, California, in 1912 was one of the most famous class conflicts over the free speech rights of labor unions. Starting out as one of several direct actions known as free speech fights carried out across North America by the Industrial Workers of the World, the catalyst of the San Diego free speech fight was the passing of Ordinance No. 4623 that banned all kinds of speech in an area that included "soapbox row" downtown. Clashes with the police in the area led to riots, multiple deaths including the deaths of police officers, as well as the retaliatory kidnapping and torture of notable Socialists, including Emma Goldman's manager Ben Reitman. As a direct result of the aftermath of this fight, the neighborhood of Stingaree was razed to the ground and the obliteration of San Diego's Chinatown.

The Industrial Workers of the World (IWW), whose members are nicknamed "Wobblies", is an international labor union founded in Chicago in 1905. The nickname's origin is uncertain. Its ideology combines general unionism with industrial unionism, as it is a general union, subdivided between the various industries which employ its members. The philosophy and tactics of the IWW are described as "revolutionary industrial unionism", with ties to socialist, syndicalist, and anarchist labor movements.