The courtroom fight over AI shopping agents just got a lot more interesting for performance marketers. On Aug. 4, 2026, the Ninth Circuit vacated the preliminary injunction that had kept Perplexity AI’s Comet browser assistant out of Amazon shopping accounts.
What the court actually said
The appeals panel zeroed in on a single question: who is doing the accessing? Under the Computer Fraud and Abuse Act, the court said, the person at the keyboard is the legal actor. Perplexity’s assistant is a tool, not a legal person.
Amazon had won an injunction in March 2026 and cleared the $5,000 loss threshold. But the appeals court found the retailer likely failed on the first element—intentional access by the defendant. Comet runs locally on a user’s device. It takes screenshots, sends them to Perplexity’s servers for instructions, and then acts in the user’s browser. Perplexity’s servers never directly hit Amazon’s systems.
The court also leaned on the rule of lenity. Because the federal hacking statute is primarily criminal, ambiguous language should not turn ordinary consumer behavior into a federal crime simply because a computer is involved. Amazon’s parallel California claim failed on the same reasoning.
The ruling doesn’t settle the larger agent accountability debate. The panel said it was not creating a legal regime for autonomous software, and it left tort and contract claims untouched. It also declined to resolve the parties’ dispute over whether Perplexity knowingly changed the assistant’s user-agent string after Amazon blocked it.
Why this rocks the retail media boat
The legal ruling is narrow, but the commercial stakes are huge. Amazon reported $19.8 billion in advertising services revenue for Q2 2026, up 26% year over year—five days before the opinion landed. Sponsored placements, recommendation carousels and other retail media surfaces are exactly the page furniture an agent can skip.
Publishers backing Amazon warned that agent traffic disguised as human activity can corrupt ad metrics. For media buyers, the problem is practical: an agent-driven session can still render pages, fire impressions and resolve to a normal browser. Separating that traffic from genuine shopper demand remains technically difficult.
What marketers should do now
The fight is shifting from litigation to detection and contracts. Amazon can still enforce its own terms of service, and it already added an agent policy in March 2026 while building an API-mediated agentic commerce team. Other platforms are likely to follow the same path.
Here’s where growth and e-commerce teams can start:
- Audit analytics for agent-like behavior: high product views, low cart events, unusual dwell patterns.
- Build separate reporting views for suspected agent traffic before optimizing retail media spend.
- Track AI shortlists and negotiated API placements as the next contested paid surface.
- Review your own marketplace terms if you operate a commerce platform.
The court did not say AI agents are free to do anything. Tort claims, contract claims and platform rules still apply. But the legal classification of who is responsible for an agent’s clicks has shifted, and measurement teams should not wait for the next appeal to catch up.
Source: PPC Land
