Supreme Court of the United States

“ By their very nature, the concepts of aiding and abetting and substantial assistance do not lend themselves to crisp, bright-line distinctions. However, both the common law and Halberstam provide some clear guideposts: The point of aiding and abetting is to impose liability on those who consciously and culpably participated in the tort at issue. The focus must remain on assistance to the tort for which plaintiffs seek to impose liability. When there is a direct nexus between the defendant’s acts and the tort, courts may more easily infer such culpable assistance. ”

“ The fact that some bad actors took advantage of these platforms is insufficient to state a claim that defendants knowingly gave substantial assistance and thereby aided and abetted those wrongdoers’ acts. And that is particularly true because a contrary holding would effectively hold any sort of communication provider liable for any sort of wrongdoing merely for knowing that the wrongdoers were using its services and failing to stop them. That conclusion would run roughshod over the typical limits on tort liability and take aiding and abetting far beyond its essential culpability moorings. ”

“ But not all of the content on defendants’ platforms is so benign. As plaintiffs allege, ISIS and its adherents have used these platforms for years as tools for recruiting, fundraising, and spreading their propaganda. Like many others around the world, ISIS and its supporters opened accounts on Facebook, YouTube, and Twitter and uploaded videos and messages for others to see. Like most other content on those platforms, ISIS’ videos and messages were then matched with other users based on those users’ information and use history. ”

“ The point of those factors is to help courts capture the essence of aiding and abetting: participation in another’s wrongdoing that is both significant and culpable enough to justify attributing the principal wrongdoing to the aider and abettor. The Ninth Circuit thus erred in focusing (as it did) primarily on the value of defendants’ platforms to ISIS, rather than whether defendants culpably associated themselves with ISIS’ actions. ”

“ That is because tort law imposes liability only when someone commits an actual tort; merely agreeing to commit a tort or suggesting a tortious act is not, without more, tortious. See Prosser & Keeton 324; Halberstam, 705 F. 2d, at 479. [11] “Enterprises” or “conspiracies” alone are therefore not tortious—the focus must remain on the tort itself. The same is true here: The ATA opens the courthouse doors only if the plaintiff is “injured ... by reason of an act of international terrorism.” ”

“ Plaintiffs assert that it is “the person,” and defendants insist that it is the “act of international terrorism.” So, plaintiffs contend, defendants can be liable if they aided and abetted ISIS generally—there is no need for defendants to have aided and abetted the specific Reina nightclub attack. Conversely, defendants posit that they are liable only if they directly aided and abetted the Reina nightclub attack, with a strict nexus between their assistance and that attack. Neither side is quite right. ”

“ Indeed, there is not even reason to think that defendants carefully screened any content before allowing users to upload it onto their platforms. If anything, the opposite is true: By plaintiffs’ own allegations, these platforms appear to transmit most content without inspecting it.
The mere creation of those platforms, however, is 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. But the same could be said of cell phones, email, or the internet generally. ”

“ To organize and present all those advertisements and pieces of content, defendants have developed “recommendation” algorithms that automatically match advertisements and content with each user; the algorithms generate those outputs based on a wide range of information about the user, the advertisement, and the content being viewed. So, for example, a person who watches cooking shows on YouTube is more likely to see cooking-based videos and advertisements for cookbooks, whereas someone who likes to watch professorial lectures might see collegiate debates and advertisements for TED Talks. ”

“ But, again, if aiding-and-abetting liability were taken too far, then ordinary merchants could become liable for any misuse of their goods and services, no matter how attenuated their relationship with the wrongdoer. ”

“ Once on the platforms, users can upload messages, videos, and other types of content, which others on the platform can then view, respond to, and share. As noted above, billions of people have done just that. As a result, the amount of content on defendants’ platforms is staggering. It appears that for every minute of the day, approximately 500 hours of video are uploaded to YouTube, 510,000 comments are posted on Facebook, and 347,000 tweets are sent on Twitter. ”

“ And the Court’s view of the facts—including its characterizations of the social-media platforms and algorithms at issue—properly rests on the particular allegations in those complaints. Other cases presenting different allegations and different records may lead to different conclusions.
The Court also draws on general principles of tort and criminal law to inform its understanding of §2333 (d) (2) . General principles are not, however, universal. The common-law propositions this Court identifies in interpreting §2333 (d) (2) do not necessarily translate to other contexts. ”

“ For example, a defendant might be held liable for aiding and abetting the burning of a building if he intentionally helped others break into the building at night and then, unknown to him, the others lit torches to guide them through the dark and accidentally started a fire. ”

“ Notably, plaintiffs never allege that ISIS used defendants’ platforms to plan or coordinate the Reina attack; in fact, they do not allege that Masharipov himself ever used Facebook, YouTube, or Twitter.
None of those 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.” ”

“ To be sure, plaintiffs assert that defendants’ “recommendation” algorithms go beyond passive aid and constitute active, substantial assistance. We disagree. By plaintiffs’ own telling, their claim is based on defendants’ “provision of the infrastructure which provides material support to ISIS.” App. 53. Viewed properly, defendants’ “recommendation” algorithms are merely part of that infrastructure. All the content on their platforms is filtered through these algorithms, which allegedly sort the content by information and inputs provided by users and found in the content itself. ”

“ They were allegedly injured by a terrorist attack carried out by ISIS. But plaintiffs are not suing ISIS. Instead, they have brought suit against three of the largest social-media companies in the world—Facebook, Twitter (who is petitioner) , and Google (which owns YouTube) —for allegedly aiding and abetting ISIS. As plaintiffs allege, ISIS has used defendants’ social-media platforms to recruit new terrorists and to raise funds for terrorism. Defendants allegedly knew that ISIS was using their platforms but failed to stop it from doing so. ”

“ In those cases, the defendants would arguably have offered aid that is more direct, active, and substantial than what we review here; in such cases, plaintiffs might be able to establish liability with a lesser showing of scienter. But we need not consider every iteration on this theme. In this case, it is enough that there is no allegation 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. ”

“ Thus, Hamilton did aid and abet Welch in burglarizing Halberstam’s home—and, as noted above, killing Halberstam was a foreseeable consequence of that burglary. See ibid.
On the other hand, defendants overstate the nexus that §2333 (d) (2) requires between the alleged assistance and the wrongful act. To start, aiding and abetting does not require the defendant to have known “all particulars of the primary actor’s plan.” ”

“ B. Marr, How Much Data Do We Create Every Day? Forbes, May 21, 2018. On YouTube alone, users collectively watch more than 1 billion hours of video every day. See YouTube Advertising, Reach Your Customers—and Discover New Ones, https://youtube.com/intl/en_us/ads/how-it-works/set-up-a-campaign/audience.
Defendants profit from this content largely by charging third parties to advertise on their platforms. Those advertisements are placed on or near the billions of videos, posts, comments, and tweets uploaded by the platforms’ users. ”

“ Still others have explained that “ [c] ulpability of some sort is necessary to justify punishment of a secondary actor,” lest mostly passive actors like banks become liable for all of their customers’ crimes by virtue of carrying out routine transactions. ”

“ And, in the process, defendants allegedly have profited from the advertisements placed on ISIS’ tweets, posts, and videos.
Plaintiffs also provide a set of allegations specific to Google. According to plaintiffs, Google has established a system that shares revenue gained from certain advertisements on YouTube with users who posted the videos watched with the advertisement. As part of that system, Google allegedly reviews and approves certain videos before Google permits ads to accompany that video. ”

“ Moreover, both criminal and tort law typically sanction only “wrongful conduct,” bad acts, and misfeasance. J. Goldberg, A. Sebok, & B. Zipursky, Tort Law: Responsibilities and Redress 31 (2004) . Some level of blameworthiness is therefore ordinarily required. ”

“ At least for Facebook and YouTube, those numbers are even higher today. See Meta Platforms, Inc., Form 10–K for Fiscal Year Ended Dec. 31, 2022, p. 56 (nearly 3 billion) ; L. Ceci, Statista, YouTube–Statistics & Facts (Mar. 22, 2023) , https://www.statista.com/topics/2019/youtube/#topicOverview (2.56 billion) .
Everyone before us today agrees on the basic aspects of these platforms’ business models. People from around the world can sign up for the platforms and start posting content on them, free of charge and without much (if any) advance screening by defendants. ”