Traditionally a terrorist attack was defined as a surprise attack involving the deliberate use of violence against civilians in order to attain political or religious goals. Terrorist attacks have typically been against single targets — individuals, buildings, or institutions. Today, more sophisticated physical attacks may also exploit the emerging vulnerabilities associated with the complexity and interconnectedness of infrastructures.
Bombs — even homemade ones — have always been able to damage a pipeline, electrical power transformer, telecommunications switching station, or microwave relay antenna. In the networked world of today, the effects of such physical attacks could spread far beyond the radius of a bomb blast. Adding to physical vulnerability is the fact that information readily available on the World Wide Web (WWW) may disclose to a terrorist the best place to set explosive charges for maximum disruptive effects.
Dependence on the information and communications infrastructure has created new cyber vulnerabilities, which are only beginning to be understood. In addition to the disruption of information and communications, countries also face the possibility that someone will be able to actually mount an attack against other infrastructures by exploiting their dependence on computers and telecommunications .