A "Scrub" and Her Bed—the Plank, Jacob Riis (1892)

A police reporter turned social reformer, Riis charged into the tenements of lower Manhattan to capture unsuspecting denizens at night. He used a magnesium- and gunpowder-filled pistol as a flash to expose society's "other half." The subjects were often asleep, intoxicated, or too tired to consent.

Courtesy of the Museum of the City of New York

Hague Conference, Erich Salomon (1930)

Courtesy of the SFMOMA

Secuencia rescate de un suicide en la cúpula el toreo (Suicide rescue from the top of the Toreo Stadium) (detail), Enrique Metinides (1971)

Courtesy of the SFMOMA

Iraq Perspectives II #8, Benjamin Lowy (2003-2007)

Courtesy of Benjamin Lowy

Urban Warfare Training Center, Panorama, Tze'elim, Shai Kremer (2007)

Courtesy of the SFMOMA

The Queen plays with her Corgies from the series Confidential, Alison Jackson (2007)

Courtesy of the artist and the M + B Gallery

San Francisco, Richard Gordon (2004)

Courtesy of the SFMOMA

Nan and Brian in Bed, New York City (1983), detail from The Ballad of Sexual Dependency, Nan Goldin (1976-1996)

Courtesy of the Matthew Marks Gallery

What Makes Jackie Run? Central Park, New York City, October 4, 1971, Ron Galella (1971)

Courtesy of the SFMOMA

[Subway Passenger, New York], Walker Evans (1941)

Courtesy of the SFMOMA

Head #10, from the series Heads, Philip-Lorca diCorcia (2001)

Courtesy of David Zwirner

San Francisco, Bill Dane (1973)

Courtesy of the SFMOMA

Greta Garbo in the Club St. Germain, Georges Dudognon (ca. 1950s)

Courtesy of the SFMOMA

Anita Ekberg and Husband Anthony Steel, Vecchia Roma, Tazio Secchiaroli (1958)

Courtesy of the SFMOMA

Men’s shoes with camera hidden in heel (n.d.)

Courtesy of the National Museum of American History Photographic History

Untitled, Miroslav Tichý (ca. 1950s-1980s)

Courtesy of the SFMOMA

The Electrocution of Ruth Snyder, Tom Howard (1928)

To get this New York Daily News shot, the first-ever published photograph of an execution, Howard planted one camera on his chest for confiscation and strapped another to his calf. Snyder had murdered her husband with the help of her lover; Howard caught her death by raising his pant leg and pulling a cable threaded up to his pocket.

Courtesy of the SFMOMA

Atlanta, Harry Callahan (1984)

Courtesy of the Pace/MacGill Gallery

Untitled, from the portfolio Tulsa, Larry Clark (1971)

Courtesy of the SFMOMA

Compact, from The Dating Surveillance Project, Laurie Long (1998)

Courtesy of the SFMOMA

Chemical and Biological Weapons Proving Ground/Dugway, UT/Distance ~42 miles/10:51 a.m., 2006, Trevor Paglen (2006)

Courtesy of the SFMOMA

Assassination of John F. Kennedy, November 22, 1963, Abraham Zapruder (1963)

Courtesy of the SFMOMA

Stranger No. 2, Shizuka Yokomizo (1999)

Courtesy of the SFMOMA

New York, Garry Winogrand (1969)

Courtesy of the Fraenkel Gallery

Lovers on the Beach, Coney Island, Weegee (Arthur H. Fellig) (1940)

Courtesy of the International Center of Photography / Getty Images

Blow Job (film still), Andy Warhol (1964)

Courtesy of The Andy Warhol Museum

Paris Hilton is seen through the window of a police car as she is transported from her home to court by the Los Angeles County Sheriff’s Department in Los Angeles on Friday, June 8, 2007, Nick Ut (2007)

Courtesy of the Associated Press

Suffolk, Virginia, Race Confrontation, May 6, 1964, United Press International (1964)

Courtesy the SFMOMA

Untitled, Kohei Yoshiyuki (1971)

The advent of infrared-sensitive film and filtered flashbulbs let Yoshiyuki photograph sex acts clandestinely in Tokyo parks. For this series, called The Park, he documented not only the prurient activities but also the voyeurs who lurked in the shadows.

Courtesy of Yossi Milo Galleru