Cite as: 598 U. S. ____ (2023) 5 Opinion of the Court and use history. And, like most other content, advertisements were displayed with ISIS’ messages, posts, and videos based on information about the viewer and the content being viewed. Unlike most other content, however, ISIS’ videos and messages celebrated terrorism and recruited new terrorists. For example, ISIS uploaded videos that fundraised for weapons of terror and that showed brutal executions of soldiers and civilians alike. And plaintiffs allege that these platforms have been crucial to ISIS’ growth, allowing it to reach new audiences, gain new members, and spread its message of terror. Plaintiffs also allege that defendants have known that ISIS has used their platforms for years. Yet, plaintiffs claim that defendants have failed to detect and remove a substantial number of ISIS-related accounts, posts, and videos. (For example, plaintiffs aver that defendants “have failed to implement . . . a basic account detection methodology” to prevent ISIS supporters from generating multiple accounts on their platforms. App. 150.) Accordingly, plaintiffs assert that defendants aided and abetted ISIS by knowingly allowing ISIS and its supporters to use their platforms and benefit from their “recommendation” algorithms, enabling ISIS to connect with the broader public, fundraise, and radicalize new recruits. 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. Plaintiffs allege that Google has reviewed and approved at least some ISIS videos under that system, thereby sharing some amount of revenue with ISIS.