§ 2331 defines "international terrorism" and "domestic terrorism" for purposes of Chapter 113B of the Code, entitled "Terrorism":
"International terrorism" means activities with the following three characteristics:
Involve violent acts or acts dangerous to human life that violate federal or state law;
Appear to be intended (i) to intimidate or coerce a civilian population; (ii) to influence the policy of a government by intimidation or coercion; or (iii) to affect the conduct of a government by mass destruction, assassination, or kidnapping; and

occur primarily outside the territorial jurisdiction of the U.S., or transcend national boundaries in terms of the means by which they are accomplished, the persons they appear intended to intimidate or coerce, or the locale in which their perpetrators operate or seek asylum. Media spectacle
A definition proposed by Carsten Bockstette at the George C. Marshall European Center for Security Studies, underlines the psychological and tactical aspects of terrorism:

Terrorism is defined as political violence in an asymmetrical conflict that is designed to induce terror and psychic fear (sometimes indiscriminate) through the violent victimization and destruction of noncombatant targets (sometimes iconic symbols). Such acts are meant to send a message from an illicit clandestine organization. The purpose of terrorism is to exploit the media in order to achieve maximum attainable publicity as an amplifying force multiplier in order to influence the targeted audience(s) in order to reach short- and midterm political goals and/or desired long-term end states. Terrorists attack national symbols, which may negatively affect a government, while increasing the prestige of the given terrorist group or its ideology.
Studies of infested lakes and outbreaks in Europe and North America have found cases where infection risk appears to be evenly distributed around the margins of water bodies as well as instances where risk increases in endemic swimmers itch "hotspots". Children may become infected more frequently and more intensely than adults but this probably reflects their tendency to swim for longer periods inshore, where cercariae also concentrate. Stimuli for cercarial penetration into host skin include unsaturated fatty acids, such as linoleic and linolenic acids. These essential fatty acids are found in many edible crops, derived plant oils, sun lotions and creams based on plant oils. Control
Various strategies targeting the mollusc and avian hosts of schistosomes have been used by lakeside residents in recreational areas of North America to deal with outbreaks of swimmers itch. In Michigan, for decades, authorities used copper sulfate as a molluscicide to reduce snail host populations and thereby the incidence of swimmers itch. The results with this agent have been inconclusive, possibly because:

Snails become tolerant
Local water chemistry reduces the molluscicides efficacy
Local currents diffuse it
Adjacent snail populations repopulate a treated areaMore importantly, perhaps, copper sulfate is toxic to more than just molluscs, and the effects of its use on aquatic ecosystems are not well understood.Another method targeting the snail host, mechanical disturbance of snail habitat, has been also tried in some areas of North America and Lake Annecy in France, with promising results. Some work in Michigan suggests that administering praziquantel to hatchling waterfowl can reduce local swimmers itch rates in humans.