nimoca: unauthorized access to the usage history service

From about midnight on 4 October, the usage history service for the nimoca transit IC card was accessed by a third party. It came to light when a user reported an unexpected email: the service's automatic emails had been triggered, sending messages with part of the registered details to registered addresses. 521 records leaked, with card numbers, birth dates and emails. The service was stopped at 17:40 that day and reopened on 15 October after measures against automated access and program fixes.