 It is first known to have appeared in 2002 in the wake of the February 12 congressional hearings titled "The Threat of Eco-Terrorism" which discussed groups including the Earth Liberation Front (ELF) and the Animal Liberation Front (ALF).In late 2005 and early 2006, as part of "Operation Backfire", US grand juries indicted a total of 18 activists on a range of charges related to "violent acts in the name of animal rights and environmental causes".According to the FBI, many of these acts were carried out on behalf of the ELF and was considered as one of the largest arrests of environmental activists in American history.