The Billboard Liberation Front practices culture jamming via altering billboards by changing key words to radically alter the message, often to an anti-corporate message. It started in San Francisco in 1977.
Advertising executives informed Jill Posener, author of Spray it Loud (1982), that the executives designed billboards to attract attacks because the changes drew attention to the products. The BLF were aware of this possibility and considered invoicing advertisers including Chiat Day for the BLF's work.
In 2013, Complex Magazine named the BLF #27 of The 50 Most Influential Street Artists of All Time.
The BLF cooperated with a range of other art groups, like Guerrilla Girls, monochrom and Joey Skaggs.
The Billboard Liberation Front -- a loosely knit Bay Area underground organization that for 23 years has "improved" billboards in San Francisco by changing advertising messages with a decidedly countercultural sensibility
Subvertising is not a new idea - the Billboard Liberation Front, which started in San Francisco in 1977, is one milestone.