In the wake of the terrorist attacks on the World Trade Center in New York City on September 11, 2001, the line between radical environmental protest (sometimes called ecoanarchism) and terrorism became blurred by strong emotions on all sides. Environmentalists in America have long held passionate beliefs about protecting the environment and saving threatened species from extinction, as well as treating animals humanely and protesting destructive business practices. One of the first and greatest environmentalists, Henry David Thoreau (1817–1862), wrote about the doctrine of "civil disobedience," or using active protest as a political tool. The author Edward Abbey (1927–1989) became a folk hero among environmentalists when he wrote the novel, The Monkey Wrench Gang, in 1975. In that book, a group of militant environmentalists practiced monkey-wrenching, or sabotaging machinery in desperate attempts to stop logging and mining. Monkey-wrenching, in its destruction of private property, goes beyond civil disobedience and is unlawful. The American...