Eleven people have been charged in the US for an alleged five-year arson spree that justice officials called a "vast eco-terrorist conspiracy".
The Animal Liberation Front became active in the US in 1979
A total of 65 charges were laid for the attacks in five western states which the Animal Liberation Front and Earth Liberation Front admitted carrying out.
The 11 were known as The Family. Three are still at large.
The damage to the targets, including forest ranger stations and meat processing plants, ran to $23m (£13m).
Other targets included the Vail skiing area, a wild horse facility, a power line and timber companies.
The attacks took place in the states of Oregon, Washington, Colorado, Wyoming and California from 1996 to 2001.
The charges were announced by US Attorney General Alberto Gonzales and the FBI's director, Robert Mueller.
Mr Gonzales said the indictment told a story "of arson, vandalism, violence and destruction" by "extremist movements known to support acts of domestic terrorism".
It is alleged the five women and six men engaged in a conspiracy to firebomb businesses using devices made from kitchen timers, milk jugs and petrol.
Mr Gonzales said the 11 used intimidation and coercion to try to influence the conduct of government and private businesses.
Mr Mueller said terrorism was terrorism, no matter what the motive.
The justice department said the conspirators took oaths to protect each other from the police and FBI - making it a long and difficult investigation.
One of the defendants in custody is a fire-fighter, another works in a home for the disabled.
The three at large - Joseph Dibee, Josephine Overaker and Rebecca Rubin - are believed to be living outside the US.
Last May, senior FBI counter-terrorism expert John Lewis said so-called eco-warriors had committed 1,200 criminal acts between 1990 and 2004 in the US, causing millions of dollars of damage.