A former temporary worker dispatched to a unit of Nippon Telegraph and Telephone West illegally leaked some 9 million sets of customer information, the unit and another subsidiary of the telecommunications company said Tuesday.
The leaked information included addresses, names and phone numbers. Credit card information was included in 81 cases, according to the two NTT West units, NTT Business Solutions and NTT Marketing Act ProCX, both based in Osaka.
The former temporary employee worked for NTT Business Solutions from June 2008 to July this year, engaged in the maintenance and management of a call center system server in which customer information and other data were stored and holding the right of free access to the server and downloading data.