Billboard Liberation Front

The Billboard Liberation Front (BLF) is a San Francisco-based artistic collective known for culture jamming and subvertising through the unauthorized alteration of outdoor advertising. Its members typically modify existing billboards by changing words, images or slogans so that the original commercial message is redirected into parody, political commentary or anti-corporate critique.

The group began in San Francisco in 1977 as an offshoot of the Suicide Club. It became one of the best-known examples of billboard alteration within culture jamming, and has been discussed in journalism, art criticism and academic writing on public space, advertising and urban prank culture.