Government officials and IT security specialists have documented a significant increase in Internet probes and server scans since early 2001. There is a growing concern among federal officials that such intrusions are part of an organized effort by cyberterrorists, foreign intelligence services, or other groups to map potential security holes in critical systems. A cyberterrorist is someone who intimidates or coerces a government or organization to advance his or her political or social objectives by launching computer-based attack against computers, network, and the information stored on them.
Even before the September 11, 2001, terrorist attacks, the U.S. government considered the potential threat of cyberterrorism serious enough that is established the National Infrastructure Protection Center in February 1998. This function was transferred to the Homeland Security Department’s Information Analysis and Infrastructure Protection Directorate to serve as a focal point for threat assessment, warning, investigation, and response for threats or attacks against US critical infrastructure, which provide telecommunications, energy, banking and finance, water systems, government operations, and emergency services. Successful cyberattacks against the facilities that provide these services could cause widespread and massive disruptions to the normal function of our society.
Cyberterrorism in general, can be defined as an act of terrorism committed through the use of cyberspace or computer resources. As such, a simple propaganda in the Internet, that there will be bomb attacks during the holidays can be considered cyberterrorism. At worst, cyberterrorist may use the Internet or computer resources to carry out an actual attack.
Source : wikipedia