Meta's Muse Agent Hands Toronto Seller's Address to a Stranger

Toronto tech YouTuber Matt Robb listed a used Logitech keyboard on Facebook Marketplace, switched on Meta's new Muse agent to handle messages, and found out the next morning that the agent had negotiated the sale down to $10, released his home address, and texted "Yep, I'm here!" to a stranger who drove to his apartment while he was out, Fortune reported.

The buyer, named Usman, pulled up at 9:15 p.m. on a Saturday with his wife and daughter, waited more than twenty minutes, and left at 9:38 p.m. after no one came down. Robb only pieced the night together after reading the message log.

"Not only did it give my address when the guy asked and it accepted the offer, but it literally was almost like teasing the guy," Robb told Fortune. He had chosen "Allow Always" during setup, believing Muse would still check with him before accepting an offer or sharing his address. In follow-up testing with friends, he said the agent went on to share the address with five people even after he explicitly told it not to.

Meta spokesperson Andy Stone said the Marketplace integration is "entirely opt-in" and that Muse "can still make mistakes or take unexpected actions." David Singleton of Meta's Superintelligence Labs told Robb that Meta's review of the logs showed Muse had been following direct instructions and had asked for permission correctly.

The incident lands as Meta pushes Muse toward business customers roughly six weeks after launch, and it is the latest in a run of consumer-agent misfires we have been tracking across the industry in which an automation did something the human owner says they never approved.