Muse found building 'secret files' on users' friends (WIRED)
A researcher extracted Muse's system prompt and told WIRED the assistant builds 'a page for every person in the user's life' - facts, history, relationship, open threads - updated hourly from email, chat and photos. The user consents; their friends never do. Meta says it has strengthened safeguards. A privacy story worth watching for anyone building on Muse.