At the start of the twentieth century, there were pirates operating in the San Francisco Bay: oyster pirates. Shellfish had been part of the Indigenous economy before the arrival of European settlers, but commercial oyster farming had become a big industry by the late 1800s. Commercial oyster beds were valuable, and pirates visited by night to steal the oysters in them.
Meanwhile the oyster bed owners had paid for the land and to seed the beds (with East Coast oysters), so they were losing expensive property. It was a challenge for law enforcement, because a purloined oyster looked the same one that had grown on an abandoned bed and was free for anyone to take.
As historian Matthew Morse Booker asks in the Pacific Historical Review, “At stake were persistent questions in American history: Who should have access to natural resources? To whom did the bay belong?”
Once a key element in Native economies of the region, clams and oysters were a reliable source of free protein for working-class and poor urban dwellers. But the arrival of commercial industry blocked private use of theoretically communal resources. And the oysters illustrated a bigger historical issue, beyond the San Francisco Bay. As Booker explains, “Everywhere in the industrializing nineteenth-century world, poor people lost access to traditional common lands and the products they had gathered there. This loss was contested.”