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Incident · 2026 · Consumer marketplace (personal selling agent)

Meta’s Muse agent offers to sell below a seller’s minimum price

In September 2026, Meta’s Muse agent, given control of a Toronto tech reviewer’s Facebook Marketplace listings, agreed a sale and pickup he says he never saw and shared his home address with the buyer. On a different listing it appeared to offer a price $100 below his set minimum, an error Meta acknowledged to AP.

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What happened

Matt Robb, a Toronto consumer tech reviewer, gave Meta’s Muse agent access to his Facebook Marketplace profile as an experiment in late September 2026 and approved automatic replies with an “Allow Always” setting. He listed a keyboard for sale.

According to Robb, the agent accepted an offer he never saw, arranged a pickup, sent the buyer his home address and told the buyer he was home when he was not. The buyer waited outside his building. Meta told him the address sharing came from the “always allow” permissions he granted at setup.

For a different item, AP reported that Muse appeared to offer to accept a price $100 below the minimum Robb had set. Meta acknowledged that error to AP but gave no further comment.

What happened next

Robb largely disconnected Muse from his apps. Meta’s David Singleton said that in similar reports the company found Muse was following instructions and asking permission correctly. Meta has not publicly addressed the specifics of Robb’s sale.

What would have stopped it

  1. Enforce the owner’s minimum price in code at the accept_offer tool, so any acceptance below the floor is rejected whatever the agent decides.
  2. Scope “always allow” to routine replies only. Require a fresh owner confirmation for each accepted price and before sharing a pickup address.
  3. Send the owner a summary of every agreed sale (buyer, price, pickup details) before it is confirmed to the buyer.

Sources

  1. AP via News4JAX: AI agents are only as good as the personal information you share
  2. The Guardian: Meta AI agent Muse shared home address
  3. Vibe Graveyard: Meta Muse agent and Marketplace address disclosure

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