Hart, Lindsay, In Defence of Radical Direct Action: Reflections on Civil Disobedience, Sabotage and Nonviolence , In Parkis, Jan ; Bowen, James , Twenty-First Century Anarchism: Unorthodox Ideas for a New Millennium London, Cassell, , 1997, pp. 214, pp. 41-59 Defends new forms of radical direct action, including ‘ecotage’, arguing that violence should be measured by harm inflicted, not use of physical force.