How the Anti-Terrorism Act Enables Civil Lawsuits Against Terror Sponsors

Most people think of terrorism law exclusively in criminal terms — prosecutors charging defendants, grand juries, federal sentencing guidelines. But there is a powerful parallel civil track: private lawsuits brought by victims and their families directly against the financial and organizational backers of terrorism. The Anti-Terrorism Act (ATA), codified at 18 U.S.C. § 2333, is the engine that drives these cases.

The Statutory Foundation: 18 U.S.C. § 2333

Congress enacted the ATA in 1992 as part of the Federal Terrorism Statutes. Section 2333(a) creates a civil cause of action for any U.S. national who is injured "by reason of an act of international terrorism." The statute provides for treble damages — three times the plaintiff's actual damages — plus costs and attorney's fees. This trebling provision is critical: it transforms a $1 million actual damage award into a $3 million judgment.

"International terrorism" under the ATA requires: (1) violent acts or acts dangerous to human life that violate U.S. criminal laws; (2) acts that appear to be intended to intimidate or coerce a civilian population, influence government policy by intimidation or coercion, or affect government conduct by mass destruction, assassination, or kidnapping; and (3) acts that occur primarily outside the United States or transcend national boundaries.

Primary Liability vs. Secondary Liability

The ATA establishes two theories of liability that plaintiffs use in practice.

Primary Liability (Direct Claims)

A primary liability claim under § 2333(a) requires the defendant to have directly committed, planned, or authorized the terrorist act. These claims are most often brought against the terrorist organization itself — though collecting on judgments against designated foreign terrorist organizations (FTOs) is extremely difficult because their assets are typically frozen or hidden.

Secondary Liability: Aiding and Abetting

The Justice Against Sponsors of Terrorism Act (JASTA), enacted in September 2016, added § 2333(d) to the ATA. This provision creates secondary liability for any person who aids and abets, by knowingly providing substantial assistance, or who conspires with a person who commits an act of international terrorism. JASTA specifically amended the Foreign Sovereign Immunities Act (FSIA) to allow ATA suits against foreign governments in cases involving state-sponsored terrorism against U.S. nationals on U.S. soil.

Landmark Cases

Several cases have shaped the landscape of ATA civil litigation over the past three decades.

Boim v. Holy Land Foundation (7th Cir. 2008)

The Seventh Circuit's en banc opinion in Boim established that secondary liability under the ATA requires: (1) that the defendant knew of the organization's illegal terrorist activities; (2) that the defendant knowingly provided material support; and (3) that the material support was a proximate cause of the plaintiff's injury. This knowledge standard has been applied in dozens of subsequent cases.

Linde v. Arab Bank (2d Cir. 2015 and 2017)

The Arab Bank litigation, brought by hundreds of victims of Hamas attacks in Israel, established important precedents regarding the admissibility of evidence in ATA cases, including government designations and regulatory findings. The case ultimately settled for a confidential amount after a jury verdict was vacated on procedural grounds.

Twitter v. Taamneh (U.S. Supreme Court, 2023)

The Supreme Court's 9-0 ruling in Twitter v. Taamneh clarified the aiding-and-abetting standard under JASTA. The Court held that defendants must have "knowingly" provided "substantial assistance" to the specific terrorist act at issue — general awareness that a platform might be used by terrorists is not enough. The ruling narrowed ATA claims against social media companies but left intact claims against banks and financial institutions that processed specific transactions for designated terrorist organizations.

Material Support and Financial Institutions

The most successful ATA cases against deep-pocketed defendants have targeted banks and financial service companies that processed wire transfers, maintained accounts, or cleared transactions for designated terrorist organizations or their known financial facilitators. Courts have found liability where:

• A bank processed transactions for an entity on the U.S. Treasury's Specially Designated Nationals (SDN) list
• A money services business transferred funds to entities known to funnel money to Hamas or Hezbollah
• A foreign bank cleared U.S. dollar transactions through a correspondent U.S. bank for an IRGC-affiliated entity
• A financial institution ignored compliance red flags that would have alerted a reasonable institution to the terrorist financing risk

Sovereign Immunity and JASTA's Narrow Exception

Before JASTA, foreign governments were largely immune from ATA suits under the FSIA. JASTA created a narrow exception: a foreign state loses its immunity from ATA claims if (1) the terrorist act occurred on U.S. soil, (2) the foreign state (or an official, employee, or agent acting within the scope of their employment) committed an act of international terrorism, and (3) the foreign state was designated as a state sponsor of terrorism at the time of the act or was later so designated.

This has opened the door to litigation against Saudi Arabia in connection with the September 11 attacks, though those cases continue to work through complex sovereign immunity questions. The JASTA exception is intentionally narrow — Congress sought to address September 11 specifically while limiting broader diplomatic consequences.

Practical Considerations for Plaintiffs

1. Identify every potential defendant — including financial institutions, foreign governments, and indirect supporters
2. Preserve and gather evidence of the defendant's awareness of and support for the terrorist organization
3. File within the 10-year statute of limitations
4. Coordinate civil litigation strategy with any pending criminal cases to avoid jeopardizing testimony
5. Understand that collection on judgments — particularly against foreign states — may require separate legal proceedings domestically and abroad

ATA civil litigation is complex, expensive, and often takes years to resolve. But for families of terrorism victims who deserve accountability from the organizations and governments that made the attack possible, it remains one of the most powerful tools available.