Twitter, Inc. v. Taamneh
The Supreme Court ruled unanimously that social media companies cannot be held legally responsible for a terrorist attack simply because ISIS used their platforms — even if the companies knew about it and failed to remove the content.
The decision sets a high bar for terrorism aiding-and-abetting claims against tech platforms: plaintiffs must show the companies consciously and substantially helped carry out a specific attack, not merely that they tolerated terrorist content on massive, publicly available networks.
How it got here: The federal district court dismissed the complaint; the Ninth Circuit reversed, finding the aiding-and-abetting claims sufficient; Twitter petitioned the Supreme Court, which agreed to hear the case.
The Case in Depth
What happened
Nawras Alassaf was killed when a gunman attacked the Reina nightclub in Istanbul on New Year's Eve 2017, acting on behalf of ISIS. Alassaf's family sued Facebook, Twitter, and Google, claiming those companies knowingly allowed ISIS to use their platforms and recommendation algorithms to recruit members, raise funds, and spread propaganda for years. The families did not allege the platforms were used to plan or coordinate the specific nightclub attack.
The question before the Court
Can family members of a terrorism victim sue Facebook, Twitter, and Google for aiding and abetting ISIS, based on the companies knowingly allowing ISIS to use their platforms and recommendation algorithms to recruit and fundraise?
The Court's answer
No — the Court ruled unanimously that the families could not hold Facebook, Twitter, and Google liable as aiders and abettors of ISIS under the federal Antiterrorism Act. The companies provided generally available platforms and content-recommendation algorithms without giving ISIS any special assistance or encouragement, and the families never alleged ISIS used those platforms to plan the Reina attack. At bottom, the complaint described defendants as passive bystanders who failed to remove ISIS content — not as conscious, culpable participants in a terrorist attack.
The Court held that aiding-and-abetting liability requires more than knowing a bad actor uses your services and failing to stop them. A plaintiff must show the defendant consciously and substantially helped carry out the specific terrorist act at issue — or was so pervasively and systematically intertwined with the terrorist organization that it effectively aided every attack. Allegations of neutral, arm's-length service to billions of users, some of whom happened to be terrorists, fall far short of that standard.
Curious how the Court got there? See the step-by-step legal reasoning →
Why it matters
Victims of terrorist attacks who sue social media companies under federal law will need to allege far more than that the companies knew terrorists used their services and failed to remove them. The ruling protects platforms that passively host content from being swept into terrorism liability, but leaves open the possibility that more deliberate or targeted assistance to a terrorist group could still give rise to a claim.
What changes now
The Ninth Circuit's ruling reinstating the lawsuit is undone, and the families' claims are dismissed. Future lawsuits against social media platforms under JASTA's aiding-and-abetting provision must allege conscious, culpable participation in a specific attack — not just failure to remove terrorist content. This case was decided the same day as the companion case Gonzalez v. Google, which involved materially identical allegations and was resolved per curiam in light of this ruling.
What this does not decide
The Court did not decide whether social media companies could ever be liable under JASTA with different allegations — for instance, if a platform consciously and selectively promoted terrorist content or provided unusually dangerous services to a known terrorist group. It also left open whether any duty requires communications providers to remove customers using their services for illegal ends.
Concurrences and dissents
Concurrence — Justice Jackson
Justice Jackson joined the majority opinion but wrote separately to stress how narrow the ruling is. She noted that both this case and its companion arrived at the Supreme Court at the earliest possible stage — a motion to dismiss, with no factual record — so the Court's characterizations of the platforms and algorithms rest entirely on the specific complaint allegations before it. Different facts or a fuller record could lead to different conclusions. She also cautioned that the common-law principles the Court uses to interpret JASTA do not automatically carry over to other legal settings.
How the Court got there
The legal reasoning, step by step
- The Court started with the text of JASTA (the 2016 Justice Against Sponsors of Terrorism Act), which allows civil suits against anyone who 'aids and abets, by knowingly providing substantial assistance' an act of international terrorism. Because Congress gave no statutory definition, the Court turned to the common-law meaning of 'aids and abets' and to Halberstam v. Welch — a 1983 D.C. Circuit case Congress explicitly endorsed as the proper legal framework for the statute.
- Drawing on Halberstam and the broader common-law tradition it distilled, the Court identified three requirements for civil aiding-and-abetting liability: (1) the principal committed a wrong; (2) the defendant was generally aware of its role in the overall illegal activity; and (3) the defendant 'knowingly and substantially' assisted the wrongdoer. The knowing and substantial elements work together — a weak showing on one demands a stronger showing on the other before a court can infer conscious, culpable participation.
- The Court emphasized that aiding-and-abetting liability has never been boundless. It requires conscious, culpable participation in wrongdoing — not mere passive failure to act. Our legal system generally does not punish bystanders, mail carriers, or service providers whose offerings are incidentally misused; some affirmative, blameworthy conduct associating the defendant with the wrongful act is required before liability attaches.
- The Court also clarified what must be aided: not a terrorist organization in the abstract, but the specific act of international terrorism that injured the plaintiff. A strict one-to-one nexus is not always required — liability can reach foreseeable consequences of assisted torts, and a defendant's role in an organization can be so pervasive and systematic that it effectively aids every act of that enterprise. But 'substantial assistance to a transcendent enterprise' floating above any particular attack is not enough.
- Applying this framework, the Court found the allegations fatally lacking. Defendants offered publicly available platforms with content-neutral recommendation algorithms; ISIS received no special treatment or encouragement; and there was no allegation that ISIS used the platforms to plan the Reina attack. Defendants' failure to remove ISIS content amounts to passive nonfeasance — which requires an especially strong showing of intent and assistance before liability attaches, a showing the families did not make.
- The Court separately addressed Google-specific allegations that it reviewed and approved ISIS videos for a revenue-sharing program. Because the complaint said nothing about how much money was shared, how many accounts were approved, or what the videos contained, there was no plausible basis to conclude Google's assistance was substantial enough to establish liability for the Reina attack — let alone for every ISIS attack worldwide, as the families' theory would require.
Doctrinal impact
Cases affected by this decision
Reaffirms Nye & Nissen v. United States (336 U. S. 613)
Repeatedly cited as the definitive standard requiring a defendant to associate with and seek to make a wrongful venture succeed.