Ninth Circuit Frees Perplexity's Comet Agent to Shop Amazon, Vacating an Injunction

Ninth Circuit Frees Perplexity's Comet Agent to Shop Amazon, Vacating an Injunction

The Vault — AI Edition | Policy | Story No. 13 | August 5, 2026

A federal appeals court has handed the AI industry its first major appellate win over the question of whether software agents can roam the web on a user's behalf, ruling that Perplexity's Comet browser is not a hacker just because it shops.

On August 4, the U.S. Court of Appeals for the Ninth Circuit vacated a preliminary injunction that had barred Perplexity's AI-powered Comet browser from operating on Amazon, finding the e-commerce giant unlikely to win its claim that the startup broke the nation's premier anti-hacking law. The three-judge panel sent the case back to the U.S. District Court for the Northern District of California for further proceedings, lifting a block that had been in place, on and off, since a lower court granted it in March.

The person-versus-tool line

At the heart of the dispute is a deceptively simple question: when Comet's optional AI Assistant logs into a shopper's Amazon account and comparison-shops on command, who is actually accessing Amazon's servers?

The Ninth Circuit's answer was the user, not Perplexity. That distinction is decisive under the Computer Fraud and Abuse Act (CFAA), the 1986 statute Amazon invoked alongside California's Comprehensive Computer Data Access and Fraud Act (CDAFA). Both laws hinge on unauthorized computer 'access.'

'The CFAA contemplates access by a person,' the panel wrote. 'However advanced the [AI] Assistant currently is, it is a tool, not a person for statutory purposes.' Because the Assistant operates at the direction of the account holder, the court reasoned, it is the human user who accesses Amazon, using Comet the way one might use any browser. Even when Perplexity received account information from users and fed it to the Assistant, the court found, that did not amount to the kind of control needed to pin 'access' on the company itself.

A narrow ruling, deliberately

The panel was pointed about the limits of its holding. Agentic AI, it acknowledged, raises novel questions, and there is 'little to no existing caselaw directly dealing with how to ascribe responsibility for AI agents like the Assistant, let alone caselaw specifically dealing with agentic AI in the CFAA context.'

Rather than resolve those questions, the court sidestepped them. It declined to establish a new legal regime for agentic AI, declined to decide whether Perplexity could dodge liability under other theories such as tort claims, and confined its holding to the meaning of 'access' under the CFAA. The court also found Amazon had not shown irreparable harm or that the public interest favored a block, warning that the injunction could restrict innovation.

The reasoning tracks the Ninth Circuit's own web-scraping precedents, including hiQ Labs v. LinkedIn and the Supreme Court's 2021 Van Buren decision, both of which narrowed the CFAA's reach. The court leaned on the rule of lenity, construing the criminal statute's ambiguity against liability.

Parties and advocates react

Perplexity cast the outcome as a vindication of consumer rights. Spokesperson Jesse Dwyer said the company 'will continue to fight for the right of internet users to choose whatever AI they want,' adding that Perplexity had 'always been confident the truth will prevail and the rights of users will not be chipped away.'

The Electronic Frontier Foundation, which filed an amicus brief, celebrated the decision. Writing for the group, attorney Andrew Crocker noted the court had credited EFF's brief as the filing that 'articulates the nature of the system most clearly,' and argued the ruling checks a familiar pattern in which 'big players use the CFAA to bully upstarts and innovators.' The court pointedly observed that Amazon's theory, taken to its logical end, 'could expose users themselves to criminal liability.'

Amazon has maintained that Perplexity re-enabled agentic shopping after an earlier pause and disguised Comet's bot as an ordinary Chrome browser to evade detection, framing the conduct as unauthorized intrusion rather than ordinary browsing.

What to watch

This is a preliminary-injunction ruling, not a final judgment. The case now returns to Judge in the Northern District of California, where Amazon can still press its CDAFA claim, pursue trespass or breach-of-contract theories tied to its terms of service, and build a fuller factual record about how Comet interacts with its servers. The Ninth Circuit was careful to leave those doors open.

The broader stakes reach well past one retailer. Every marketplace, booking platform, and SaaS provider now weighing whether to welcome or wall off AI agents has its first appellate signpost, and it points toward treating agents as user tools rather than trespassers. Expect other platforms to respond with technical blocks and revised terms of service, and expect the next round of litigation, over tort liability, contract, and the CDAFA, to test just how far the person-versus-tool line can stretch as agents grow more autonomous.

--- Sources: Courthouse News Service, Engadget, Electronic Frontier Foundation, Reuters/Yahoo Finance, Bloomberg Law, No Hacks. Ninth Circuit opinion, Amazon.com Inc. v. Perplexity AI Inc. (No. 26-1444).