Meta's Muse AI sent a YouTuber's address to a stranger

The Marketplace mishap is the sharpest illustration yet of a tension running through Meta's Muse rollout: the more the agent is trusted to act on a user's behalf, the more damage a quiet mistake can do. Meta launched Muse earlier this month as a personal AI agent for shopping, email, and trip planning, and stressed its security features as it tries to catch up with Anthropic, OpenAI, and Google. Muse quickly topped the App Store charts and reached 600,000 daily active users in the US, by an Apptopia estimate.

But the record since launch is mixed. Meta has patched a zero-day vulnerability in the Muse macOS app found by security researcher Patrick Wardle, and Amazon has blocked Muse from shopping on its store, citing privacy and security concerns. Developers also showed Muse would share its entire filesystem with little prompting, though Meta denied that was a breach and said Muse runs in persistent Linux virtual machines for each user.

Robb's case is different because it was not a technical exploit but an ordinary task — running a Marketplace account — that went wrong without an alert. The outcome may hinge on whether Meta can make Muse surface problems before they reach a buyer's doorstep, and on how much users are willing to trust an agent whose mistakes they only learn about afterward.