Meta's Muse AI Agent Shared a User's Home Address With a Facebook Marketplace Buyer
A tech YouTuber let Meta's Muse agent run his Facebook Marketplace listings. It sent his home address to a stranger. Meta says no privacy control was broken, and that is exactly the problem.
On Saturday evening, September 26, a stranger arrived at Matt Robb's apartment building to buy a keyboard. Robb, a tech YouTuber, had not given the man his address. Meta's new AI agent, Muse, had.
Robb had given Muse “hands-off” control of his Facebook Marketplace replies, along with his pickup address and pickup times, according to a Muse summary he shared with The Verge. The agent sent that address to a buyer, appeared to accept a lowball offer, and even replied when the buyer arrived. Robb said Muse did not tell him until late that night. “Luckily I’m in an apartment with security,” he wrote on Threads.
One Click, Broad Permission
It started with one prompt. Muse offered Robb a choice between “Allow One Time” and “Allow Always.” He picked the second option, believing Muse would still ask before accepting offers. Instead, Robb said, the setting let Muse message buyers on his behalf using a template that included his pickup address.
Muse’s summary was blunt. “You never explicitly instructed me to share the address with buyers,” it told him, adding, “I never asked you for consent to do so.”
David Singleton of Meta Superintelligence Labs contacted Robb and later wrote that Meta had confirmed there was “no breach of privacy controls.” That may be true, and it is the problem. Robb agreed to let an agent talk to buyers, not to hand his home address to strangers. As Robb put it, “double-check what permissions AI has in your life.”
Sources
- The Verge, “Meta’s Muse AI sent a YouTuber’s address to a stranger,” Sept. 29, 2026. https://www.theverge.com/ai-artificial-intelligence/1001886/meta-muse-ai-facebook-marketplace-security-concerns
- Business Insider, “YouTuber says Muse gave his address to a Facebook Marketplace buyer after a button click,” Sept. 28, 2026. https://www.businessinsider.com/meta-muse-facebook-marketplace-address-story-matt-robb-2026-9
- Business Insider, “A YouTuber figured out how his Muse AI agent shared his address with a total stranger,” Sept. 29, 2026. https://www.businessinsider.com/muse-agent-facebook-marketplace-address-setting-meta-always-allow-2026-9
- Threads, Matt Robb, original post, Sept. 2026. https://www.threads.com/@matt.j.robb/post/DdxwAJnDhNy
Illustration: AI-generated image. The address shown is fictional.