It was another tough week to be Phoebe Gates.  Bloomberg’s latest investigation found Gates and cofounder Sophia Kianni knew for seven months that their AI shopping extension, Phia, was quietly taking credit for sales it never drove—not just the 24 hours the company initially claimed. The trick, called “cookie stuffing,” had Phia silently hijacking checkout pages to swap in its own referral code over legit ones, until Bloomberg revealed the practice in tests of more than 50 sites.  Phia says it killed the feature, is reversing bad transactions, and is hiring a compliance chief. Whether that’s enough to keep the…