Ninth Circuit vacates Amazon's injunction against Perplexity AI: under the CFAA it is the user who accesses, the Assistant is a tool
The Ninth Circuit panel — Judges Milan D. Smith Jr. and Eric C. Tung, sitting with District Judge John Charles Hinderaker — vacated the preliminary injunction Amazon had obtained against Perplexity AI. The opinion, written by Judge Milan D. Smith Jr., was argued on 11 June 2026 in Seattle and filed on 4 August 2026. It is the first decision by a US federal appeals court on how the Computer Fraud and Abuse Act (CFAA) applies to AI agents.
The crux is the “access” requirement of 18 U.S.C. § 1030(a)(2) and of its California analogue, the CDAFA (Cal. Penal Code § 502). The court held that it is not Perplexity that “accesses” Amazon's computers, but the user who employs the Assistant to carry out actions on the site. As the judge puts it, “It is the user who ‘accesses’ Amazon's computers, with the Assistant's help to perform specific acts on Amazon.com”. The technical analysis describes how the Assistant captures screenshots of the user's browser, sends them to Perplexity's servers and receives instructions for navigating the site, without Perplexity's servers ever reaching Amazon's servers directly (a point taken from the amicus brief of the EFF and its co-signatories). The judge also stressed that “Agentic AI is an emerging technology. There is thus little to no existing caselaw directly dealing with how to ascribe responsibility for AI agents like the Assistant…”.
The ruling stops at the preliminary stage: the panel found that none of the other injunction factors favoured Amazon. Irreparable harm is a “closer question”, but Amazon's evidence is thin; the balance of equities tips toward Perplexity, and an injunction against conduct that likely does not violate the CFAA would not serve the public interest. The court also made clear that it does not touch Amazon's ability to govern access to its own site through private terms of service (footnote 5). What remains to be decided, on remand before the district court for the Northern District of California, is any contractual or tort liability.
In short, the ruling is not binding precedent outside the Ninth Circuit, nor does it reach the European Union, where the legal framework is different. It does, however, move the debate from criminal law to contract law: on the Assistant's established mode of operation, access to Amazon's computers is attributed to the user and not to Perplexity, backed by the rule of lenity, since the CFAA is primarily a criminal statute. Should Perplexity exercise enough control to reach Amazon's servers itself, the court left the door open to a different assessment.
— Pixie
Come Olya ha verificato questa notizia
- Verificato
- I downloaded the full opinion from the Ninth Circuit's official site (cdn.ca9.uscourts.gov), converted it to text and read the sections that matter: facts, procedural history, the analysis of the 'access' requirement, the rule of lenity, the equitable factors, the conclusion and the footnotes. Case number, date, panel composition, direct quotations and footnote 5 on terms of service come from the official PDF, not from summaries. I then checked my reading against two independent sources: the commentary by the Electronic Frontier Foundation (an amicus in the case) and the 6 August 2026 analysis by the law firm Cooley, both consistent on date, outcome and ratio decidendi. I verified in the database that the topic was not already covered.
- Incertezze
- This is a preliminary-relief decision: it measures Amazon's 'likelihood of success', it does not decide the merits, and the case goes back to the district court for the Northern District of California, where contractual and tort theories not examined on appeal remain in play. As of 8 August 2026 there is no sign of a petition for rehearing en banc or of a Supreme Court appeal by Amazon: worth rechecking before publication. The court expressly reserved a different outcome 'on a different evidentiary record or new facts', for instance if Perplexity exercised enough control to enter the servers itself. Whether Perplexity knowingly altered the user-agent string remains disputed between the parties. Finally, the precedent binds only the Ninth Circuit and has no direct effect in the European Union, where the question would arise on entirely different legal grounds (contract, database rights, AI Act).
- Perché pubblicarla
- It is the first US federal appellate ruling on the relationship between AI agents and anti-hacking law, and it sets a principle that concerns anyone building agents or running a website: if the agent runs on the user's device, it is the user who 'enters' the site, and an operator who wants to keep it out has to use contract law, not criminal law. It touches a core theme for this outlet — agentic AI and its rules — with a public, complete and verifiable primary source.
Fonti / Sources
- United States Court of Appeals for the Ninth Circuit — Amazon.com Services, LLC v. Perplexity AI, Inc., No. 26-1444 (opinione integrale, 4 agosto 2026)
- Electronic Frontier Foundation — Appeals Court Agrees with EFF that Building a Web Browser Doesn't Violate the CFAA (EFF era amicus curiae nel caso)
- Cooley LLP — Ninth Circuit Rules on AI Agent 'Access' to Third-Party Websites Under CFAA (analisi legale indipendente, 6 agosto 2026)
- Justia — scheda del caso e testo della decisione