Supreme Court Finds Tech Companies Not Liable for Terrorism

Last week, the Supreme Court decided two cases in which plaintiffs alleged that social media companies aided and abetted international terrorism. In the first case, Twitter, Inc. v. Taamneh, the Justices unanimous interpreted the Antiterrorism Act’s (ATA) provision on aiding and abetting to require conscious and culpable participation. Plaintiffs’ allegations that ISIS used defendants’ social media platforms and that the companies did little to prevent such use, the Court held, did not satisfy that requirement.

The Supreme Court disposed of the second case, Gonzalez v. Google LLC, on the same ground in a brief, per curiam opinion. The Court thus avoided the question that it originally granted cert to answer: whether Section 230 of the Communications Decency Act immunizes interactive computer services that make targeted recommendations.

Aiding and Abetting Under the ATA

In 1990, Congress created a civil cause of action for U.S. nationals injured by international terrorism. In 2016, as part of the Justice Against Sponsors of Terrorism Act (JASTA), Congress amended this provision to create liability “as to any person who aids and abets, by knowingly providing substantial assistance, or who conspires with the person who committed such an act of international terrorism.” JASTA’s preamble pointed to the D.C. Circuit’s decision in Halberstam v. Welch (1983) as providing “the proper legal framework” for aiding and abetting claims under the ATA.

Although the Justice seemed divided at oral argument, the Court’s opinion in Twitter was unanimous, with only Justice Jackson adding a brief concurrence to emphasize its limits. Writing for the Court, Justice Thomas stressed “the common-law tradition” from which Halberstam arose and noted that JASTA pointed only to Halberstam’s “framework” and “not its facts or its exact phrasings and formulations.” Having shaken off the directions that Congress tried to give, the Court emphasized “the need to cabin aiding-and-abetting liability to cases of truly culpable conduct.” Otherwise, “ordinary merchants could become liable for any misuse of their goods and services, no matter how attenuated their relationship with the wrongdoer.” “The phrase ‘aids and abets’ in § 2333(d)(2), as elsewhere,” the Court held, “refers to a conscious, voluntary, and culpable participation in another’s wrongdoing.”

The Court proceeded to consider “what precisely a defendant must aid and abet,” the person or the act. Justice Thomas found it unnecessary to parse the text of the statute to answer this question “because aiding and abetting is inherently a rule of secondary liability for specific wrongful acts.” “Thus, it is not enough,” the Court said, “that a defendant have given substantial assistance to a transcendent ‘enterprise’ …. Rather, a defendant must have aided and abetted (by knowingly providing substantial assistance) another person in the commission of the actionable wrong—here, an act of international terrorism.”

The Twitter plaintiffs failed to allege that the defendants culpably associated themselves with ISIS’s terrorist attack in Istanbul. Merely creating social media platforms was not culpable. “To be sure, it might be that bad actors like ISIS are able to use platforms like defendants’ for illegal—and sometimes terrible—ends,” the Court observed. “But the same could be said of cell phones, email, or the internet generally.” The recommendations produced by the defendants’ algorithms did not amount to substantial assistance. “All the content on their platforms is filtered through these algorithms,” the Court noted. “The fact that these algorithms matched some ISIS content with some users thus does not convert defendants’ passive assistance into active abetting.”

“At bottom,” the Court continued, “the claim here rests less on affirmative misconduct and more on an alleged failure to stop ISIS from using these platforms.” But the Court was “leery” of imposing liability “for mere passive nonfeasance.” “To show that defendants’ failure to stop ISIS from using these platforms is somehow culpable with respect to the [ISIS] attack,” the Court explained, “a strong showing of assistance and scienter would … be required. Plaintiffs have not made that showing.”

It is worth noting the sharp contrast between the Supreme Court’s narrow interpretation of “aiding and abetting” under the ATA in Twitter and its broad interpretation of “material support” under the ATA in Holder v. Humanitarian Law Project (2010). In Holder, the Court rejected the argument that material support required specific intent to further an organization’s terrorist activities and read the provision to cover support intended to promote peaceful and lawful activities. “Such support frees up other resources within the organization that may be put to violent ends,” the Court reasoned. “It also importantly helps lend legitimacy to foreign terrorist groups.” Writing at TLB, Maryam Jamshidi worried that Holder’s broad approach to material support might color its interpretation of aiding and abetting. But Twitter treated aiding and abetting quite differently from material support and did not even mention Holder.

But Twitter’s impact on aiding and abetting claims outside the social media context may be limited. Social media platforms, once established, operate automatically. The same is not necessarily true of banking services, for example. In 2021, the Second Circuit held that U.S. citizens injured in rocket attacks against Israel launched by Hezbollah had stated an aiding and abetting claim against a Lebanese bank. It is possible that the Second Circuit might reevaluate that conclusion in light of Twitter. On the other hand, a court might reasonably conclude that banks know more about their customers than social media platforms know about their users, making the provision of banking services sufficiently culpable to state a claim for aiding and abetting under Section 2333. As Justice Jackson cautioned in her concurring opinion, “[o]ther cases presenting different allegations and different records may lead to different conclusions.”

Section 230

The second decision involved Section 230 of the Communications Decency Act, which provides: “No provider or user of an interactive computer service shall be treated as the publisher or speaker of any information provided by another information content provider.” The Ninth Circuit held that Google’s targeted recommendations of content were entitled to immunity under this provision because they were content neutral. Plaintiffs challenged that conclusion before the Supreme Court, arguing that targeted recommendations are not “information provided by another” but rather information provided by the computer service itself.

But the Court found it unnecessary to address this question. “[M]uch (if not all) of plaintiffs’ complaint seems to fail under either our decision in Twitter or the Ninth Circuit’s unchallenged holdings below,” the Court explained in an unsigned opinion. “We therefore decline to address the application of § 230 to a complaint that appears to state little, if any, plausible claim for relief.”

At oral argument, the parties presented divergent arguments that would have granted either broad immunity to internet companies’ efforts to organize information or very little, resisting some Justices’ attempts to find a middle ground. In the end, the Court decided to leave the issue to Congress. We are “not like the nine greatest experts on the Internet,” Justice Kagan observed at argument. The result, however, is to leave in place the Ninth Circuit’s broad interpretation of Section 230 until Congress acts.


The Supreme Court’s decisions in the Google and Twitter cases present an odd combination of deference to Congress and lack of deference. With respect to Section 230, the Court gave up on interpreting the statute and punted the question to Congress. With respect to the ATA’s aiding and abetting provision, by contrast, the Court cast aside Congress’s interpretive guidance and imposed its own narrow construction.