As regards the interception of communications, Article 3 of the Wiretapping Act authorises such measures only under strict requirements. In particular, the public authorities have to obtain a prior court warrant that may only be issued for the investigation of specific serious crimes (listed in the Annex to the Act) (85) and when it is "extremely difficult to identify the criminal or clarify the situations/details of the perpetration by any other ways" (86). Under Article 5 of the Wiretapping Act, the warrant is issued for a limited period of time and additional conditions may be imposed by the judge. Moreover, the Wiretapping Act provides for a number of further guarantees, such as for instance the necessary attendance of witnesses (Articles 12, 20), the prohibition to wiretap the communications of certain privileged groups (e.g. doctors, lawyers) (Article 15), the obligation to terminate the wiretapping if it is no longer justified, even within the period of validity of the warrant (Article 18), or the general requirement to notify the individual concerned and allow access to the records within thirty days after the wiretapping has been terminated (Articles 23, 24).

In any event, the Administrative Organ has to take a written decision within a certain period (30 days, which under certain conditions can be extended by an additional 30 days). If the request is rejected, only partially granted, or if the individual for other reasons considers the conduct of the Administrative Organ to be "illegal or unjust", the individual may request administrative review based on the Administrative Complaint Review Act (141). In such a case, the head of the Administrative Organ deciding on the appeal shall consult the Information Disclosure and Personal Information Protection Review Board (Articles 42, 43 APPIHAO), a specialised, independent board whose members are appointed by the Prime Minister with consent of both Houses of the Diet. According to the information received, the Review Board may carry out an examination (142) and in this respect request the Administrative Organ to provide the retained personal information, including any classified content, as well as further information and documents. While the ultimate report sent to the complainant as well as the Administrative Organ and made public is not legally binding, it is in almost all cases followed (143). Moreover, the individual has the possibility to challenge the appeal decision in court based on the Administrative Case Litigation Act. This opens the way for judicial control of the use of the national security exception(s), including of whether such an exception has been abused or is still justified.