An 18-page petition filed August 18, 2026 by Hueston Hennigan LLP — Hagan Scotten, Moez M. Kaba, Christine Woodin and Billy Joe McLain — for plaintiff-appellee Amazon.com Services LLC, seeking rehearing en banc of the Ninth Circuit panel opinion of August 4, 2026 in No. 26-1444, which vacated the preliminary injunction entered by Judge Maxine M. Chesney (N.D. Cal. No. 3:25-cv-09514-MMC) against Perplexity's Comet Assistant (Amazon.com Services, LLC v. Perplexity AI, Inc., No. 26-1444 (9th Cir. Aug. 4, 2026) — Opinion). The filed document runs 63 pages, of which the last 40 reproduce the panel opinion as Addendum A. The requested relief is that the petition be granted, the opinion vacated, and the preliminary injunction reinstated.
The petition invokes Fed. R. App. P. 40(b)(2)(A) — conflict with a decision of the court — and 40(b)(2)(D) — a question of exceptional importance.
The framing
Amazon's opening move is to characterize the dispute as one about appellate standards rather than about AI doctrine. The panel, it argues, "erred in vacating the injunction" not by adopting the wrong legal rule but by "wrongly substitut[ing] an amicus's inaccurate account of the facts for those the district court found after a painstaking hearing," thereby "stripping district courts of discretion to manage the novel risks of AI during pending litigation."
Two prior en banc decisions supply the template: United States v. Hinkson, 585 F.3d 1247 (9th Cir. 2009) (en banc), where a panel's disregard of the abuse-of-discretion standard had left "no effective limit on our power to substitute our judgment for that of the district court," and United States v. Gasca-Ruiz, 852 F.3d 1167 (9th Cir. 2017) (en banc), which overruled a panel reviewing district courts de novo. The exceptional-importance argument is jurisdictional in flavour: "Disputes over AI will be litigated first, and mostly, in this Circuit's district courts," so whether those courts retain discretion to halt allegedly illegal AI uses during litigation is a question of "general importance likely to recur."
Amazon concedes the panel disclaimed "establish[ing] a new legal regime governing agentic AI" and states it "is confident that it will eventually prevail under the standard set forth by the panel, given that it is the same standard Amazon sought, Van Buren imposed, and the district court applied." The stated harm is therefore interim: that Perplexity is "taking every measure to delay a final resolution" while continuing to send the Assistant into password-protected areas.
The record Amazon says the panel displaced
The petition reconstructs the district court record at pages 2–6 with record citations. The district court ruled on "a record of eight briefs, sixteen declarations, seventy-five exhibits, and a three-and-a-half-hour hearing," and found "strong evidence" that "Perplexity, through its Comet browser, accesses . . . without authorization by Amazon, the user's password-protected account." It rejected the suggestion that "Comet's some kind of free agent that has nothing to do with Perplexity," reasoning that "Comet [acts] on behalf of Perplexity because Comet is just a thing" and that when a car malfunctions, plaintiffs "don't sue the car."
The technical findings Amazon presses are that the Assistant "depends on Perplexity's servers to operate," such that "when network access to Perplexity's servers is blocked, the Assistant spins and is unable to perform any actions"; that Perplexity supplies the "reasoning layer" deciding what actions the Assistant takes; that on a generic instruction such as "order paper towels" Perplexity directs the Assistant into the Amazon Store and employs the user's stored credentials, including in sessions that "started without the user visiting amazon.com"; and that the Assistant transmits the user's entire browsing history to Perplexity's servers "regardless of the webpage in the current tab and the user's request."
A second cluster concerns conduct rather than architecture: Amazon told Perplexity's CEO its agents were not permitted in the store before the Assistant launched; repeated the prohibition to senior management and by cease-and-desist letter; blocked the Assistant, whereupon "Perplexity devised a new version that defeated the block within twenty-four hours"; erected a second block and told Perplexity's lawyers, after which "within two days the Assistant returned to the store"; and throughout, Perplexity "disguised the Assistant as a human user so Amazon could not tell machine from customer." Amazon argues this pattern itself proves Perplexity "repeatedly chose to 'exercise control over the Assistant in such a way as to gain entry to Amazon's servers'" — quoting the panel's own reservation of that scenario for a different record.
The four assignments of error
Failure to apply Hinkson. Because the panel did not find the district court applied the wrong legal rule, Amazon argues it could reverse only under the "limited and deferential" abuse-of-discretion standard, which the panel "recited . . . but never applied." The petition says the panel "re-found facts de novo, relying on a narrative the district court never saw," introducing its dispositive discussion by block-quoting an amicus brief filed for the first time on appeal. Amazon says that account is contradicted by the record on two specifics: the amicus asserted the Assistant contacts Perplexity's servers only "[i]f necessary to carry out the task requested by the user," where the record shows constant contact; and that it merely "analyze[s] the contents of the page that has been displayed," where the record shows credential transmission and full browsing-history exfiltration. The governing authorities offered are United States v. Walker, 601 F.2d 1051 (9th Cir. 1979) (review confined to the record before the trial judge), Metcalf v. Daley, 214 F.3d 1135 (9th Cir. 2000) (striking extra-record amicus materials), and United States v. Sineneng-Smith, 590 U.S. 371 (2020), where the Supreme Court unanimously vacated a panel that restructured an appeal around amici's submissions rather than "the case shaped by the parties."
Amazon accepts the panel's inference on the panel's own premises — "If those were the only facts, that conclusion might follow" — and locates the error in the premises: Perplexity's "instructions" tell the Assistant "what to access, where to access it, how to access the secure pages, and what to do with the information obtained."
Failure to apply Power Ventures. Amazon reads Facebook, Inc. v. Power Ventures, Inc., 844 F.3d 1058 (9th Cir. 2016), as having already held that a corporation operating a program that performs actions inside password-protected areas on users' general authorization "accesses" the site. The panel declined to follow it on the ground that it "implied that Power accessed Facebook's servers" without extensive reasoning; Amazon responds that Power Ventures "did not imply this; it explicitly said that 'Power accessed Facebook's computers,'" and that a conclusion reached in the course of finding the access unauthorized is no less binding, citing United States v. Lindsey, 634 F.3d 541 (9th Cir. 2011), and United States v. Jingles, 702 F.3d 494 (9th Cir. 2012). A footnote argues the panel inverted Amazon's argument: Amazon's point was that the court attributed even Power's "relatively ministerial, user-directed" action to the company, which makes Perplexity's more elaborate control "plainly attributable."
Misapplication of the rule of lenity. Amazon argues lenity is "solely a principle of statutory interpretation," and that the panel engaged in no statutory interpretation beyond rejecting Perplexity's server-to-server definition of access; it therefore "used lenity as a factual tiebreaker for whether the evidence was sufficient," citing United States v. Freter, 31 F.3d 783 (9th Cir. 1994). On the panel's stated worry that Amazon's reading "could expose users themselves to criminal liability," Amazon answers that customers "have Amazon's permission to enter their own accounts," so "the gates are up for customers and down for Perplexity"; that aiding and abetting requires intent going "to the specific and entire crime charged" under Rosemond v. United States, 572 U.S. 65 (2014), which a user asking for paper towels lacks; and that Gebardi v. United States, 287 U.S. 112 (1932), together with United States v. Nosal, 676 F.3d 854 (9th Cir. 2012), and LVRC Holdings LLC v. Brekka, 581 F.3d 1127 (9th Cir. 2009), already place authorized users outside the CFAA — a protection never extended to "unauthorized outsiders like Perplexity."
The CDAFA. Amazon calls the state-law error "sharper still." California Penal Code § 502(b)(1) defines access as "to gain entry to, instruct, cause input to, cause output from, cause data processing with, or communicate with" a computer system. Amazon says the panel quoted that definition only in part, reciting "caus[ing] input to [or] data processing with" while omitting "instruct" and "communicate with" — "verbs that describe what the panel acknowledged Perplexity instructs the Assistant to do." The district court had treated the CDAFA as an independent ground, finding Amazon "still ha[d] shown a likelihood" of success because "you do have 502," access being "broader under 502 than it is under 1030." The petition faults the panel for disposing of that ground in one paragraph on a "rise and fall together" premise while acknowledging the "statutes are different," contrary to United States v. Christensen, 828 F.3d 763 (9th Cir. 2015), and invokes Arizonans for Official English v. Arizona, 520 U.S. 43 (1997), for caution where state law drives the outcome.
The exceptional-importance argument
The final section leans on the panel's own characterization of agentic AI as "an emerging technology" with "little to no existing caselaw." Citing Hart v. Massanari, 266 F.3d 1155 (9th Cir. 2001), Amazon argues that in such a field the first published opinion "occupies the field" and "its effects are not easily reversed," so the panel's approach "will thus be studied and applied throughout this Circuit."
Amazon uses the breadth of amicus participation on both sides as evidence of stakes while denying it as evidence of facts: retailers, airlines, trade organizations, publishers and the software industry "all explained why computer owners' authority to control who enters their password-protected systems — and to distinguish automated agents from customers — underwrites the security of the systems on which their industries depend," but "[a]lthough those submissions may establish the stakes of this case, they cannot establish the facts of this case." The closing ask is that the court "ensure that when questions of this importance are answered, they are answered on evidence," and grant review "to restore the abuse of discretion standard before the panel's error becomes the Circuit's first rule for agentic AI."
Relation to the SIIA amicus brief
The petition and the SIIA amicus brief supporting it converge on three of four grounds: the Hinkson deference failure, the unacknowledged narrowing of Power Ventures, and the collapse of the CDAFA into the CFAA contrary to Christensen. They differ in emphasis. SIIA's distinctive argument — that the panel's rule makes liability turn on where code runs rather than on operator conduct, so that identical circumvention is "unlawful when carried out by ordinary software and lawful when carried out by an agentic AI tool" — does not appear as such in the petition, which argues instead that the panel never reached that question because it decided the case on an untested factual account. Conversely, the rule-of-lenity argument is Amazon's alone. SIIA cites the petition at "Pet. 5-11" for the district court's control findings and the standard of review, corresponding to the record reconstruction and the Hinkson section above.
Provenance
Captured September 4, 2026 from CourtListener RECAP storage for Ninth Circuit docket 72502129, document 66. The docket entry records "PETITION FOR REHEARING EN BANC filed by Appellee Amazon.com Services, LLC" on August 18, 2026, and every page of the PDF carries the header stamp "Case: 26-1444, 08/18/2026, DktEntry: 66.1." The raw file reproduces the petition and its certificate of compliance; Addendum A, the panel opinion, is separately held.
Relationships
- contradicts: Amazon.com Services, LLC v. Perplexity AI, Inc., No. 26-1444 (9th Cir. Aug. 4, 2026) — Opinion — seeks vacatur of that opinion
- supports: Amazon v. Perplexity AI
- related: Brief of the Software & Information Industry Association as Amicus Curiae Supporting Rehearing En Banc — Amazon v. Perplexity (August 28, 2026) — amicus brief supporting this petition
- related: Computer Fraud and Abuse Act (CFAA) — the access element under 18 U.S.C. § 1030
- related: Amazon, Perplexity
- related: AI Agentic Browsers