摘要：As the online profiles of organisations become more important, so do their vulnerabilities to online attack. A wide range of online methods can be used to attack the credibility of an organisation, deter participation by its members and undermine its operations. A case study from the Australian vaccination debate is used to illustrate the operation and impact of some of these possible methods. The main modes of attack are disrupting discussions, dominating descriptions and ridiculing and intimidating opponents. The main modes of defence are excluding disrupters, providing counter-descriptions, making formal complaints, and ignoring or exposing abuse. New forms of social media in the future will offer additional options for both offence and defence.
