 The alternative tactic of using explosive and incendiary devices was then established in 1976, by John Hanna and others as the Environmental Life Force (ELF), also now known as the "original ELF".The group conducted a campaign of armed actions in northern California and Oregon, later disbanding in 1978 following Hanna's arrest for placing incendiary devices on seven crop-dusters at the Salinas, California airport on May Day, 1977.It wasn't until over a decade and a half later that this form of guerrilla warfare resurfaced as the Earth Liberation Front  using the same ELF acronym.