Ministry of Internal Affairs and Communications

  • Sitemap
  • japanese

Press Release

January 26, 2012

Guidance given to NTT DoCoMo, Inc. concerning Accident Prevention, Protection of Secrecy of Communication, and Suitable Control of Personal Information

 On January 26, 2012, based on incidents that have occurred with regards to mobile phone services provided by NTT DoCoMo, Inc., the Ministry of Internal Affairs and Communications (MIC) issued guidance to the company for urgent measures including prevention of recurrence, etc. and requested report on results from the implementation of these measures.

1. Background

(1) Since April 2011, there have been four serious incidents (on June 6, August 16 and December 20, 2011, and January 1, 2012) relating to the mobile phone services provided by NTT DoCoMo, Inc. (hereinafter, “NTT DoCoMo).

Apart from the incident on June 6 of last year, all of these incidents were related to smart phones, and it is thought that these occurrences can be attributed to a lack of necessary and appropriate measures taken by NTT DoCoMo to improve the reliability of NTT DoCoMo's systems as the number of smart phone users surges.

(2) In particular, according to reports from NTT DoCoMo, the incident that occurred on December 20 of last year saw leakages of users' e-mail addresses and e-mail content, etc. It has been admitted that there was leakage of secret communication, as set forth in Article 4, Item 1 of the Telecommunications Business Act (Act No. 86 of 1984), and that this violates Article 20 of the Act on the Protection of Personal Information (Act No. 57 of 2003) as well as the responsibility of safety control measures as set forth in Article 11, Item 1 of the Guidelines for Protection of Personal Information in the Telecommunications Field (2004 Ministry of Internal Affairs and Communications (MIC) Bulletin No. 695).

(3) Also, on January 25, 2012, communication difficulties occurred with mobile phone services in some parts of Tokyo.

(4) Since repeated occurrence of serious incidents such as these will cause great damage to the interests of users as well as to trust in communication services, appropriate measures are being sought.

2. Content of guidance

By means a letter issued on January 26, 2012 under the name of the Director-General of the Telecommunications Bureau, the Ministry of Internal Affairs and Communications (MIC) has given guidance to NTT DoCoMo, requesting that in line with the following items preventive measures, etc. are taken as a matter of urgency, and that actual results and future initiatives be reported back to the MIC no later than March 30 (Fri), 2012.

(1) Deployment of telecommunications equipment to provide appropriate support for increases in number of users and traffic, etc.

(2) Deployment of appropriate reserve equipment and construction of monitoring system in order to deal with occurrences of telecommunications equipment failure, etc.

(3) Prevention of congestion by means of overload experiments, etc.

(4) Protection of secrecy of communication and personal information

(5) Appropriate support for users

3. Future initiatives

The Ministry of Internal Affairs and Communications (MIC) will continue to diligently provide necessary guidance and supervision in order to guarantee the stable provision of telecommunications services.


For further information about this press release, please fill in the inquiry form and submit it to MIC on the website

International Policy Division,
Global ICT Strategy Bureau, MIC
TEL: +81 3 5253 5920 / FAX: +81 3 5253 5924

Page Top