What other forms of popular culture have spurred on social movements?

The Protestans, culture and activism from the Civil Rights Movement to the Streets, it started using art on flannels, walls, hats and banners as a means of protesting against civil rights, then he became a social movement, The Rastafarian movement, they fought and sing about subjets like the Independence of Africa, the Legality of cannabis, songs of love, with a strong social criticism or others with sexual references, they were popular culture that ended up being social movements.