Domestic surveillance within the United States has a history that is rich in lessons for our post 9/11 world.

Early in the 20th century, the threat of terrorism spurred the development of a domestic intelligence bureaucracy. The fear of “radical ideas” brought by European immigrants and a series of anarchist bombings carried out in cities across the country, including a deadly attack on Wall Street, led J. Edgar Hoover and his staff at the Justice Department’s General Intelligence Division to compile index cards on hundreds of thousands of suspects and round up thousands in the 1919-1920 Palmer Raids. As the fledgling Bureau of Investigation and the Treasury Department’s Secret Service competed for turf, private citizens and local government agencies were enlisted to be the federal government’s “eyes and ears” in the hunt for subversives.

All too often, individuals who were subjected to surveillance were wholly innocent of wrongdoing or guilty of nothing more than association with unpopular organizations and controversial ideas. Or they were targeted because of their national origin, race or religion. The World War II internment of up to 120,000 American citizens and other residents of Japanese descent was a low point in our history.

With the post World War II Red Scare and the creation of the Central Intelligence Agency and the National Security Agency, the incentive and capacity for mass surveillance took a major leap forward. The FBI’s COINTELPRO, CIA’s Operation CHAOS, and NSA’s Operation SHAMROCK were some of the programs that spied on lawful First Amendment activity. Their goal was to keep the nation “safe” by disrupting political dissent, the movements for civil rights and Black liberation, and protests against the Vietnam War, among other perceived threats.

Once the extent of government overreaching and abuse of power came to light through the investigations of the Rockefeller Commission and Church Committee in the 1970s, certain limited reforms were put in place to curb domestic spying and safeguard freedom of expression and privacy rights. But in the same period, the elements of the “surveillance society” were being assembled, as swiftly evolving computer technology gave birth to new forms of monitoring, data sharing and storage, with far-reaching implications for maintaining social control.

Before the attacks of 9/11, total information awareness was waiting in the wings.