The federal Anti-Terrorism Act (18 U.S.C. § 2333) grants a civil remedy to anyone injured “by reason of” an act of international terrorism, and includes within those who may be held liable not only the perpetrators of the terrorism but also those who knowingly give material support or resources to the particular act of terrorism or to a known terrorist organization.  This decision holds that “by reason of” incorporates the common law concept of proximate causation and that it requires more than mere foreseeability.  The defendant’s wrongful conduct must be shown to have led directly to the injury plaintiff suffered.  Here, plaintiffs could not allege such a connection between the murder of their relatives by an ISIS adherent in Jordan and Twitter’s alleged support of ISIS by allowing ISIS to open and use Twitter accounts to communicate with its adherents.

 Ninth Circuit Court of Appeal (Smith, J.); January 31, 2018; 2018 WL 626800.