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Supreme Court justices appeared broadly concerned Tuesday about the potential unintended consequences of allowing websites to be sued for their automatic recommendations of user content, highlighting the challenges facing attorneys who want to hold Google accountable for suggesting YouTube videos created by terrorist groups.

For nearly three hours on Tuesday, the nine justices peppered attorneys representing Google, the US government and the family of Nohemi Gonzalez, an American student killed in a 2015 ISIS attack, with questions about how the court could design a ruling that exposes harmful content recommendations to liability while still protecting innocuous ones.

How – or if – the court draws that line could have significant implications for the way websites choose to rank, display and promote content to their users as they seek to avoid a litigation minefield.

The attorney for the Gonzalez family argued that narrowing Section 230 of the Communications Decency Act – the federal law protecting websites’ right to moderate their platforms as they see fit – would not lead to sweeping consequences for the internet. But both the Court’s liberals and conservatives worried about the impact of such a decision on everything from “pilaf [recipes] from Uzbekistan” to individual users of YouTube, Twitter and other social media platforms.

Justices are worried about lawsuits and disruption to the internet

A big concern of the justices seems to be the waves of lawsuits that could happen if the court rules against Google.

“Lawsuits will be nonstop,” Justice Brett Kavanaugh said at one point.

But Eric Schnapper, representing the plaintiffs, argued that a ruling for Gonzalez would not have far-reaching effects because even if websites could face new liability as a result of the ruling, most suits would likely be thrown out anyway.

“The implications are limited,” Schnapper said, “because the kinds of circumstance in which a recommendation would be actionable are limited.”

Later, Justice Elena Kagan warned that narrowing Section 230 could lead to a wave of lawsuits, even if many of them would eventually be thrown out, in a line of questioning with US Deputy Solicitor General Malcolm Stewart.

“You are creating a world of lawsuits,” Kagan said. “Really, anytime you have content, you also have these presentational and prioritization choices that can be subject to suit.”

Chief Justice John Roberts mused that under a narrowed version of Section 230, terrorism-related cases might only be a small share of a much wider range of future lawsuits against websites alleging antitrust violations, discrimination, defamation and infliction of emotional distress, just to name a few.

“I wouldn’t necessarily agree with ‘there would be lots of lawsuits’ simply because there are a lot of things to sue about,” Stewart said, “but they would not be suits that have much likelihood of prevailing, especially if the court makes clear that even after there’s a recommendation, the website still can’t be treated as the publisher or speaker of the underlying third party.”

Plaintiffs struggle to draw a line between recommendations of harmful vs. non-harmful content

Multiple justices pushed Schnapper to clarify how the court should treat recommendation algorithms if the same algorithm that promotes an ISIS video to someone interested in terrorism might be just as likely to recommend a pilaf recipe to someone interested in cooking.

“I’m trying to get you to explain to us how something that is standard on YouTube for virtually anything you have an interest in, suddenly amounts to aiding and abetting [terrorism] because you’re [viewing] in the ISIS category,” Justice Clarence Thomas said.

Schnapper attempted several explanations, including at one point digressing into a hypothetical about the difference between YouTube videos and video thumbnail images, but many of the justices were lost about what he was calling for.

“I admit I’m completely confused by whatever argument you’re making at the present time,” Justice Samuel Alito said.

Roberts added: “It may be significant if the algorithm is the same across … the different subject matters, because then they don’t have a focused algorithm with respect to terrorist activities… Then it might be harder for you to say that there’s selection involved for which you can be held responsible.”

One of the few justices focusing on how changes to Section 230 could affect individual internet users was Justice Amy Coney Barrett, who repeatedly asked whether narrowing the law in the ways Schnapper has proposed could put average social media users in legal jeopardy.

The text of Section 230 explicitly immunizes “users,” and not just social media platforms, from liability for the content posted by third parties. So a change that exposes tech platforms to new lawsuits could also have implications for users, according to several amicus briefs.

Under Schnapper’s interpretation, could liking, retweeting or saying “check this out” expose individuals to lawsuits that they could not deflect by invoking Section 230?

Yes, Schnapper acknowledged, because “that’s content you’ve created.”

Barrett raised the issue again in a question for Justice Department lawyer Stewart. She asked: “So the logic of your position, I think, is that retweets or likes or ‘check this out’ for users, the logic of your position would be that 230 would not protect in that situation either. Correct?”

Stewart said there was distinction between an individual user making a conscious decision to amplify content and an algorithm that is making choices on a systemic basis. But Stewart did not provide a clear answer about how he believed changes to Section 230 could affect individual users.

Specter of defamation litigation plays a big role in arguments

Tech law experts say an onslaught of defamation litigation is the real threat if Section 230’s protections are weakened and the justices seemed to agree, posing several questions and hypothetical that turned on defamation claims.

“People have focused on the [Antiterrorism Act], because that’s the one point that’s at issue here. But I suspect there will be many, many times more defamation suits,” Chief Justice John Roberts said, while pointing to other types of claims that also may flood the legal system if tech companies no longer had broad Section 230 immunity.

Justice Samuel Alito posed for Schnapper a scenario where a competitor of a restaurant created a video making false claims about the restaurant violating health code and YouTube refusing to take the video down despite knowing its defamatory.

Kagan seized on Alito’s hypothetical later on in the hearing, asking what happens if a platform recommended the false restaurant competitor’s video and called it the greatest video of all time, but didn’t repeat anything about the content of the video.

“Is the provider on the hook for that defamation?” Kagan asked.

Dispute over Section 230’s role in the rise of the internet

Though Google’s attorney, Lisa Blatt, did not get the tough grilling that Schnapper and Stewart received, some justices hinted at some discomfort with how broadly Section 230 has been interpreted by the courts.

Justice Ketanji Brown Jackson pushed back at Blatt’s claims about Congress’ intent when it enacted the relevant provision in 1996. Blatt had claimed that Congress’ move to broadly protect tech platforms from legal liability is what got the internet off the ground.

“That the internet never would have gotten off the ground if everybody would have sued was not what Congress was concerned about at the time it enacted this statute,” Jackson said.

But a brief in the case filed by Section 230’s original authors has contradicted Jackson’s account of Section 230’s intent and purpose.

The brief, written by Oregon Democratic Sen. Ron Wyden and former California Republican Rep. Chris Cox, explained that Section 230 arose as a response to early lawsuits over how websites managed their platforms, and was intended to shelter the nascent internet.

“Congress therefore sought to encourage that evolution by enacting a technology-agnostic immunity provision that would protect Internet platforms from liability for failing to perfectly screen unlawful content,” Wyden and Cox wrote, saying that algorithmic recommendations are an example of the kind of moderation techniques Section 230 was designed to incubate.

In questions for Google’s foes, Justice Sonia Sotomayor suggested that platforms could face liability if they created a search engine that was discriminatory. She put forth an example of a dating site that wouldn’t match individuals of different races. Justice Barrett returned to the hypothetical in her questioning of Blatt.

Multiple justices – even as they were not sympathetic to the tech foes’ arguments – suggested that that Google and its allies were playing Chicken Little in the stark warnings they gave the court about how a ruling against Google would transform the internet.

“Would Google collapse and the Internet be destroyed if YouTube and therefore Google were liable for posting and refusing to take down videos that it knows are defamatory and false,” Alito asked Blatt.

Blatt said Google may withstand such legal attacks but other websites – because they’re not as big as Google – would struggle to survive.

Barrett points to a potential exit ramp

Barrett referenced an exit ramp the Supreme Court has that would allow it to avoid the big legal question over the scope of Section 230.

She pointed to the tech case the court will hear Wednesday, in which the justices will consider whether an anti-terrorism law covers internet platforms for their failure to adequate remove terrorism-related conduct. The same law is being used by the plaintiffs to sue Google in Tuesday’s case.

“So if you lose tomorrow, do we even have to reach the Section 230 question here? Would you concede that you would lose on that ground here?” Barrett asked Schnapper.

What happens Wednesday

As Barrett mentioned, there’s another big tech case on the Supreme Court’s docket Wednesday. The case, Twitter v. Taamneh, is not about Section 230 directly. Instead, the justices are considering whether social media companies can be sued for aiding and abetting an act of international terrorism after hosting content that generally expressed support for ISIS but that did not refer to a specific act of terror.

Where Google has argued that it does not have to face such a suit because of Section 230 – triggering Tuesday’s liability debate – the Twitter case being argued Wednesday hinges more directly on the substance of the Anti-Terrorism Act.

The facts in the Twitter and the Google case are similar, even if they’re posing different legal questions. And that’s why, as Barrett suggested, a finding that Twitter is not liable under the ATA might also resolve the Google case without the need to weigh in on Section 230.

Together, the two tech cases the justices are hearing this week have the potential to transform the landscape of the internet. The Supreme Court’s rulings in the cases are expected by early summer.

This story and headline have been updated with developments from Tuesday’s hearing.

CNN’s Jessica Schneider contributed to this report.