EU One-Stop-Shop Regulatory Jurisdiction Rules Content: On March 18, 2026, Rome’s regional court vacated Italy’s landmark €15 million GDPR fine against OpenAI over ChatGPT data breaches. Judges ruled that once OpenAI established its formal EU headquarters in Ireland, the Irish Data Protection Commission held exclusive lead supervisory authority under GDPR’s one-stop-shop mechanism. The judgment does not dismiss OpenAI’s underlying privacy violations, but creates critical precedent