When Can Amazon Block an Agentic AI Service?–Amazon vs. Perplexity

by guest blogger Kieran McCarthy

On March 9, 2026, Judge Chesney granted a preliminary injunction in the case of Amazon v. Perplexity, concluding Amazon was likely to succeed on its CFAA and California Penal Code section 502 theories.

If you’re familiar with the CFAA, the outcome of the preliminary injunction opinion was what you might expect.

But it is underwhelming in some new and interesting ways. It is, in my opinion, a shockingly poor effort to grapple with CFAA applicability to agentic AI technology after Van Buren.

If you’re unfamiliar, agentic AI is simply the name for AI that actually does work for you instead of answering questions. An agent can take a loose goal, break it into steps, use tools, gather information, make decisions, and come back with the task done. That makes it useful for the work people hate but still need judgment to finish, such as research, product comparisons, customer support, and multi-step coordination.

One valuable use case for agentic AI is shopping. Not only can Agentic AI tell you what the highest rated toaster on Amazon is for under $100, it can actually buy it for you.

You can tell agentic AI:

Buy a toaster on Amazon for under $100. Prioritize name brands, Amazon Prime shipping, and wide slots for bagels. Do not buy based solely on Amazon rating. Consider only models with at least 1,000 reviews, a rating of 4.7 or higher, and no obvious fake-review pattern. Cross-check at least two independent review sources or testing sites for confirmation that the quality is among the best at this price point. Choose a 2-slice toaster unless a 4-slice model is clearly better.

If one option is clearly superior under these criteria, add it to my cart and proceed to purchase. If not, add the best by these measures and I will review and purchase.

The thing about instructions like these is that they totally kill many of the ways online e-commerce sites make money. Amazon doesn’t just make money from selling you stuff and sending it to you. They also make money from product placement, ads, upselling, and a million other ways of nudging you into buying more stuff.

Amazon wants their search bar to be the way that you buy things online. But if the interface for your shopping becomes the AI labs’ platforms, that’s a big deal for e-commerce sites. It’s an existential threat to some e-commerce platforms and a major margins headwind for giants like Amazon and Walmart.

Those are the stakes.

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The injunction in this case arose from Amazon’s challenge to Perplexity’s Comet browser and shopping agent. Perplexity built a tool that allows software to shop for users on Amazon through their logged-in accounts. Amazon sent a cease-and-desist letter. But Comet didn’t stop.

Created by ChatGPT Dec. 2025