Twitter v. Taamneh

Twitter, Inc. v. Mehier Taamneh, et al.  (2023) 
Supreme Court of the United States

Note: Where it is feasible, a syllabus (headnote) will be released, as is being done in connection with this case, at the time the opinion is issued. The syllabus constitutes no part of the opinion of the Court but has been prepared by the Reporter of Decisions for the convenience of the reader. See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.



No. 21–1496. Argued February 22, 2023—Decided May 18, 2023

In 2017, Abdulkadir Masharipov carried out a terrorist attack on the Reina nightclub in Istanbul, Turkey, on behalf of the Islamic State of Iraq and Syria (ISIS), a designated Foreign Terrorist Organization. Masharipov killed Nawras Alassaf and 38 others. Alassaf’s family then brought this suit under 18 U. S. C. §2333, an Antiterrorism Act (ATA) provision that permits U. S. nationals who have been “injured … by reason of an act of international terrorism” to file a civil suit for damages. Instead of suing ISIS directly under §2333(a), the plaintiffs (respondents here) invoked §2333(d)(2) to sue three of the largest social-media companies in the world—Facebook, Twitter (petitioner here), and Google (which owns YouTube)—for aiding and abetting ISIS.

The parties today agree on the basic aspects of these platforms: Billions of people from around the world have signed up for them and upload massive amounts of content each day. Defendants profit from that content by placing advertisements on or near it and use “recommendation” algorithms that match content, advertisements, and users based on information about the use, advertisement, and content being viewed. As the parties represent things, the algorithms here match any content with any user who is more likely to view that content, and the platforms perform little to no front-end screening on any content before it is uploaded.

Plaintiffs, however, allege that for several years the companies have knowingly allowed ISIS and its supporters to use their platforms and “recommendation” algorithms as tools for recruiting, fundraising, and spreading propaganda; plaintiffs further allege that these companies have, in the process, profited from the advertisements placed on ISIS’ tweets, posts, and videos. The District Court dismissed the complaint for failure to state a claim, but the Ninth Circuit reversed.

Held: Plaintiffs’ allegations that these social-media companies aided and abetted ISIS in its terrorist attack on the Reina nightclub fail to state a claim under 18 U. S. C. §2333(d)(2). Pp. 6–31.

(a) In 2016, Congress enacted the Justice Against Sponsors of Terrorism Act (JASTA) to impose secondary civil liability on anyone “who aids and abets, by knowingly providing substantial assistance, or who conspires with the person who committed such an act of international terrorism.” §2333(d)(2). The question here is whether the conduct of the social-media company defendants gives rise to aiding-and-abetting liability for the Reina nightclub attack. Pp. 6–8.

(b) The text of JASTA begs two questions: What does it mean to “aid and abet”? And, what precisely must the defendant have “aided and abetted”? Pp. 8–21.

(1) Nothing in the statute defines any of the critical terms in the phrase “aids and abets, by knowingly providing substantial assistance.” The term “aids and abets,” however, is a familiar common-law term and thus presumably “brings the old soil” with it. Sekhar v. United States, 570 U. S. 729, 733. Congress also provided additional context in JASTA by pointing to Halberstam v. Welch, 705 F. 2d 472, as “provid[ing] the proper legal framework” for “civil aiding and abetting and conspiracy liability.” 130 Stat. 852. Halberstam’s legal framework, viewed in context of the common-law tradition from which it arose, confirms that “aids and abets” in §2333(d)(2) refers to a conscious, voluntary, and culpable participation in another’s wrongdoing. Pp. 9–17.

(i) In Halberstam, the D. C. Circuit undertook an extensive survey of the common law with respect to aiding and abetting and synthesized the surveyed cases as resting on three main elements: (1) there must be a wrongful act causing an injury performed by the person whom the defendant aided; (2) at the time assistance was provided, the defendant must have been “generally aware of his role as part of an overall illegal or tortious activity;” and (3) the defendant must have “knowingly and substantially assist[ed] the principal violation.” 705 F. 2d, at 477. The court then articulated six factors to help determine whether a defendant’s assistance was “substantial.” They are (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. Id., at 488 (emphasis deleted). Halberstam also clarified that those who aid and abet “a tortious act may be liable” not only for the act itself but also “for other reasonably foreseeable acts done in connection with it.” Id., at 484. Finally, the court warned that its formulations should “not be accepted as immutable components” but should be “adapted as new cases test their usefulness in evaluating vicarious liability.” Id., at 489. Pp. 9–11.

(ii) Because the allegations here—involving international terrorist networks and world-spanning internet platforms—are a far cry from the facts of Halberstam, the Court must ascertain the basic thrust of Halberstam’s elements to determine how to adapt them to the facts of this case. To do so, the Court turns to the common law of aiding and abetting upon which Halberstam rested, and to which JASTA’s common-law terminology points. At common law, the basic “view of culpability” animating aiding and abetting liability is that “a person may be responsible for a crime he has not personally carried out if he helps another to complete its commission.” Rosemond v. United States, 572 U. S. 65, 70. However, the concept of “helping” in the commission of a crime or a tort has never been boundless and ordinarily requires some level of blameworthy conduct; those limits ensure that aiding and abetting does not sweep in mere passive bystanders or those who, for example, simply deliver mail that happens to aid criminals. In tort law, many cases have thus required a voluntary, conscious, and culpable participation in the wrongful conduct to establish aiding and abetting. In doing so, they further articulated Halberstam’s framework to capture those limits. As above, that framework requires that the defendant give knowing and substantial assistance to the primary tortfeasor; notably, courts often viewed those twin requirements as working in tandem, with a lesser showing of one demanding a greater showing of the other to establish a conscious, culpable participation in the tort. Pp. 11–16.

(iii) Halberstam differentiated types of aid along the same culpability axis that grounded the common law. And its six factors for “substantial assistance” call for the same balancing that courts had undertaken previously between the nature and amount of assistance and the defendant’s scienter. Pp. 16–17.

(2) The parties then vigorously dispute what precisely a defendant must aid and abet under §2333(d)(2). Plaintiffs assert that it is “the person,” while defendants insist that it is the “act of international terrorism.” That syntactic dispute makes little difference here, because aiding and abetting is inherently a rule of secondary liability for specific wrongful acts. In the tort context, liability is imposed only when someone commits (not merely agrees to commit) an actual tort. And in this case, the ATA limits that liability to injuries caused by an “act of international terrorism,” §2333(a). It thus is not enough for a defendant to have given substantial assistance to a transcendent enterprise. 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. However, that does not require a strict nexus between the assistance and the wrongful act; defendants are liable for other torts that are the foreseeable risk of an intended tort, and an aider and abettor can assist someone without knowing all the details of his plan. Plus, in appropriate circumstances, a defendant’s role in an illicit enterprise can be so systemic and intentional that the defendant aids and abets each act of the enterprise—as in Halberstam itself.

To summarize the requirements of §2333(d)(2), the phrase “aids and abets, by knowingly providing substantial assistance” points to the elements and factors articulated by Halberstam. Those elements and factors should not be taken as inflexible codes but should be understood in light of the common law and applied as a framework designed to hold defendants liable when they consciously and culpably “participate[d] in” a tortious act in such a way as to help “make it succeed.” Nye & Nissen v. United States, 336 U. S. 613, 619. Pp. 17–21.

(c) Plaintiffs have satisfied Halberstam’s first two elements by alleging both that ISIS committed a wrong and that defendants knew they were playing some sort of role in ISIS’ enterprise. But plaintiffs’ allegations do not show that defendants gave such knowing and substantial assistance to ISIS that they culpably participated in the Reina attack. Pp. 21–30.

(1) Plaintiffs allege that defendants aided and abetted ISIS in the following ways: First, they provided social-media platforms, which are generally available to the internet-using public; ISIS was able to upload content to those platforms and connect with third parties on them. Second, defendants’ recommendation algorithms matched ISIS-related content to users most likely to be interested in that content. And, third, defendants knew that ISIS was uploading this content but took insufficient steps to ensure that its content was removed. Plaintiffs do not allege that ISIS or Masharipov used defendants’ platforms to plan or coordinate the Reina attack. Nor do plaintiffs allege that defendants gave ISIS any special treatment or words of encouragement. Nor is there reason to think that defendants carefully screened any content before allowing users to upload it onto their platforms.

None of plaintiffs’ allegations suggest that defendants culpably “associate[d themselves] with” the Reina attack, “participate[d] in it as something that [they] wishe[d] to bring about,” or sought “by [their] action to make it succeed.” Nye & Nissen, 336 U. S., at 619 (internal quotation marks omitted). Defendants’ mere creation of their media platforms is no more culpable than the creation of email, cell phones, or the internet generally. And defendants’ recommendation algorithms are merely part of the infrastructure through which all the content on their platforms is filtered. Moreover, the algorithms have been presented as agnostic as to the nature of the content. At bottom, the allegations here rest less on affirmative misconduct and more on passive nonfeasance. To impose aiding-and-abetting liability for passive nonfeasance, plaintiffs must make a strong showing of assistance and scienter. Plaintiffs fail to do so.

First, the relationship between defendants and the Reina attack is highly attenuated. Plaintiffs make no allegations that defendants’ relationship with ISIS was significantly different from their arm’s length, passive, and largely indifferent relationship with most users. And their relationship with the Reina attack is even further removed, given the lack of allegations connecting the Reina attack with ISIS’ use of these platforms. Second, plaintiffs provide no reason to think that defendants were consciously trying to help or otherwise participate in the Reina attack, and they point to no actions that would normally support an aiding-and-abetting claim.

Plaintiffs’ complaint rests heavily on defendants’ failure to act; yet plaintiffs identify no duty that would require defendants or other communication-providing services to terminate customers after discovering that the customers were using the service for illicit ends. Even if such a duty existed in this case, it would not transform defendants’ distant inaction into knowing and substantial assistance that could establish aiding and abetting the Reina attack. And the expansive scope of plaintiffs’ claims would necessarily hold defendants liable as having aided and abetted each and every ISIS terrorist act committed anywhere in the world. The allegations plaintiffs make here are not the type of pervasive, systemic, and culpable assistance to a series of terrorist activities that could be described as aiding and abetting each terrorist act by ISIS.

In this case, the failure to allege that the platforms here do more than transmit information by billions of people—most of whom use the platforms for interactions that once took place via mail, on the phone, or in public areas—is insufficient to state a claim that defendants knowingly gave substantial assistance and thereby aided and abetted ISIS’ acts. A contrary conclusion would effectively hold any sort of communications provider liable for any sort of wrongdoing merely for knowing that the wrongdoers were using its services and failing to stop them. That would run roughshod over the typical limits on tort liability and unmoor aiding and abetting from culpability. Pp. 21–27.

(2) The Ninth Circuit’s analysis obscured the essence of aiding-and-abetting liability. First, the Ninth Circuit framed the issue of substantial assistance as turning on defendants’ assistance to ISIS’ activities in general, rather than with respect to the Reina attack. Next, the Ninth Circuit misapplied the “knowing” half of “knowing and substantial assistance,” which is designed to capture the defendants’ state of mind with respect to their actions and the tortious conduct (even if not always the particular terrorist act). Finally, the Ninth Circuit appears to have regarded Halberstam’s six substantiality factors as a sequence of disparate, unrelated considerations without a common conceptual core. In doing so, the Ninth Circuit focused primarily on the value of defendants’ platforms to ISIS, rather than whether defendants culpably associated themselves with ISIS’ actions. Pp. 27–29.

(3) There is also one set of allegations specific to Google: that Google reviewed and approved ISIS videos on YouTube as part of a revenue-sharing system and thereby shared advertising revenue with ISIS. But the complaint here alleges nothing about the amount of money that Google supposedly shared with ISIS, the number of accounts approved for revenue sharing, or the content of the videos that were approved. Nor does it give any other reason to view Google’s revenue sharing as substantial assistance. Without more, plaintiffs thus have not plausibly alleged that Google knowingly provided substantial assistance to the Reina attack, let alone (as their theory of liability would require) every single terrorist act committed by ISIS. Pp. 29–30.

(d) The concepts of aiding and abetting and substantial assistance do not lend themselves to crisp, bright-line distinctions. Applying the guideposts provided by the common law and Halberstam, the nexus between defendants and the Reina attack is far removed. As alleged by plaintiffs, defendants designed virtual platforms and knowingly failed to do “enough” to remove ISIS-affiliated users and ISIS-related content from their platforms. Yet, plaintiffs have failed to allege that defendants intentionally provided any substantial aid to the Reina attack or otherwise consciously participated in it—much less that defendants so pervasively and systemically assisted ISIS as to render them liable for every ISIS attack. Plaintiffs accordingly have failed to state a claim under §2333(d)(2). Pp. 30–31.

2 F. 4th 871, reversed.

Thomas, J., delivered the opinion for a unanimous Court. Jackson, J., filed a concurring opinion.
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