From Center for Democracy & Technology:

The Center for Democracy & Technology (CDT) and six other civil society organizations that support free expression rights filed an amicus brief in Twitter v. Taamneh, a case before the U.S. Supreme Court. In Taamneh, the Court will interpret the Anti-Terrorism Act (ATA) to determine when an online intermediary can be held liable for aiding and abetting an act of international terrorism. The Court will consider the case in tandem with Google v. Gonzalez, which presents the question Section 230 immunizes online intermediaries from ATA liability (CDT also plans to file an amicus brief in Gonzalez.)

The amicus brief in Taamneh urges the Supreme Court to interpret the ATA to hold that a defendant cannot be held liable based on its function as a speech intermediary unless it has actual knowledge that a specific piece of user-generated content on its platform provides substantial assistance to a terrorist act.

The plaintiffs in Taamneh are family members of the victims of terrorist attacks by the Islamic State, also known as ISIS. They seek damages from Twitter and other social media companies under the ATA, claiming that they violated the law by allowing ISIS to use its platform to recruit members and spread its propaganda and threats. The Ninth Circuit denied Twitter’s motion to dismiss, holding that the plaintiffs adequately alleged a claim under the ATA because Twitter was generally aware that ISIS members used its service and its efforts to remove terrorist content were insufficiently “meaningful” and “aggressive.”

Our amicus brief supports Twitter’s appeal and urges the Supreme Court to reverse the holding below. The amicus brief explains that the Court has long recognized that the First Amendment forbids not just direct regulation of protected speech, but also state action likely to cause self-censorship and the curtailment of lawful speech. In a series of cases dating back to the 1950s, the Court has acknowledged that imposing liability on speech intermediaries (like booksellers or magazines) for the speech they publish or distribute can have chilling effects, if the level of knowledge required for liability is too low. The amicus brief urges the Court to interpret the ATA in keeping with that precedent and hold that aiding and abetting liability premised on speech requires a showing that a online intermediary had actual knowledge that a specific piece of user-generated content substantially assists an act of terrorism.

The amicus brief also argues that it would substantially chill individuals’ speech to allow online intermediaries to be held liable under the ATA for aiding and abetting based on mere “generalized knowledge” that alleged terrorists or their affiliates use their services. This standard would effectively require platforms to over-remove content or otherwise sharply limit the content they allow users to post. Intermediaries already rely on blunt tools to moderate the vast amounts of speech that users post every day, which already cause them to take down content mistakenly identified as offensive or forbidden. Faced with potential ATA liability, the amicus brief argues, online platforms like Twitter will even more aggressively moderate content. As a result, large amounts of societally beneficial and constitutionally protected user-generated speech will be removed or forbidden, and users will have less access to information, especially on controversial topics like terrorism.

The other organizations joining the amicus brief are the American Civil Liberties Union, the American Civil Liberties Union Of Northern California, Electronic Frontier Foundation, Knight First Amendment Institute At Columbia University, R Street Institute, and Reporters Committee for Freedom of the Press. CDT is grateful to our pro bono counsel, Cooley LLP, for its work on this amicus brief.