United States – Microsoft

In a rare security blunder, Microsoft failed to secure a backend server for Bing. The server is estimated to have leaked more than 6.5TB of log files containing 13 billion records originating from the Bing search engine. The leak included the server exposed technical details, such as search queries, details about the user’s system (device, OS, browser, etc.), geo-location details (where available), and various tokens, hashes, and coupon codes.