Clifford Chance

On May 18, the Supreme Court held in Twitter v. Taamneh that the family of a victim killed in ISIS's 2017 terror attack in Istanbul could not sue tech companies for aiding and abetting the attack.

Plaintiffs had successfully argued at the United States Court of Appeals for the Ninth Circuit that Facebook, Twitter, and Youtube (via its corporate parent, Google) knew that ISIS used their platforms and nevertheless allowed its activities to continue. The Ninth Circuit therefore concluded that the plaintiffs' claims under the Anti-Terrorism Act ("ATA" or "the Act"), 18 USC § 2333, could survive a motion to dismiss because ISIS had derived significant value from the defendants' platforms, even if not specifically for the Istanbul attack. The Supreme Court reversed that decision.

The Anti-Terrorism Act

The Anti-Terrorism Act, 18 USC § 2333, provides a civil cause of action to victims of acts of international terrorism against perpetrators of such attacks. In 2016, Congress expanded liability under the Act to explicitly allow plaintiffs to sue individuals and entities who aided and abetted an act of terrorism "by knowingly providing substantial assistance[.]" 18 USC § 2333(d)(2). Congress did not provide a definition of "aiding and abetting" but pointed to the US Court of Appeals for the District of Columbia Circuit's analysis of common-law secondary liability in Halberstam v. Welch, 705 F.2d 472 (1983), as instructive.

Plaintiffs have successfully used the ATA's secondary liability provision to exert real pressure on multinationals and financial institutions in recent years, reaching trial on multiple occasions. However, splits between courts have arisen in part due to confusion regarding the application of the six-factor test for "knowingly providing substantial assistance" explained in Halberstam, which involves "(1) the nature of the act assisted, (2) the amount of assistance provided, (3) whether the defendant was present at the time of the principal tort, (4) the defendant’s relation to the tortious actor, (5) the defendant’s state of mind, and (6) the duration of the assistance given." Slip Op. at 10.

The Taamneh Decision

The Supreme Court reversed the Ninth Circuit's decision, applying Halberstam as informed by the common law to conclude that the plaintiffs' claims cannot be sustained against the tech companies because aiding and abetting under the ATA means "conspicuous, voluntary, and culpable participation" in the principal wrongdoing. The Court emphasized that Halberstam's factors are flexible and need not be strictly applied. Instead, the Court explained, the factors should be balanced together to determine the depth of the defendant's consciousness of the wrong and culpability.

The Court specifically corrected the Ninth Circuit's interpretation of the "knowing" and "substantial" requirements, holding that (1) the defendant must have culpably participated and (2) the defendant must have supported an actionable wrong rather than a terrorist organization generally (unless the support is so systemic as to blur with the concept of conspiracy). These two requirements interact with each other, and where one is strong, a lesser showing on the other may be required.

The Court found that the tech companies neither knowingly nor substantially participated in the 2017 Istanbul attack. As to substantial assistance of the attack, the plaintiffs failed to allege that any of the attack's planning took place on one of the platforms in question, or that the attacker even used the platforms. The tech companies also did not take any affirmative actions with respect to ISIS, engaging in only "passive nonfeasance," which does not rise to the level of substantial assistance. As to the "knowing" requirement, the Court noted that the tech companies each have hundreds of millions of users, are generally available to the public, and use neutral infrastructures and algorithms that defendants created but do not regularly influence. In combination, and given the implications if a US victim could sue over an ISIS attack that took place anywhere in the world, the Court held that the tech companies could not be subject to aiding and abetting liability for the 2017 attack.

Implications

The Supreme Court's decision articulates a more concrete, detailed, and perhaps higher standard for the ATA's aiding and abetting liability than previously existed. However, plaintiffs will undoubtedly attempt to differentiate the decision regarding tech company defendants which, in the Supreme Court's words, have an "arms-length, passive, and largely indifferent relationship" with their customers, from companies in other industries. The Court's lengthy and fact-laden analysis includes a number of clues — including a favorable quotation from a lower court's decision warning against holding "mostly passive actors like banks . . . liable for all of their customers’ crimes by virtue of carrying out routine transactions." Slip Op. at 15 (quoting Monsen v. Consolidated Dressed Beef Co., 579 F.2d 793, 799 (3d Cir. 1978)). The presence of distinguishing affirmative conduct could change the analysis, ensuring that ATA litigation over secondary liability will continue.