General legal framework
As an exercise of public authority, government access in Japan must be carried out in full respect of the law (legality principle). In this regard, the Constitution of Japan contains provisions limiting and framing the collection of personal data by public authorities. As already mentioned with respect to processing by business operators, basing itself on Article 13 of the Constitution which among others protects the right to liberty, the Supreme Court of Japan has recognised the right to privacy and data protection (72). One important aspect of that right is the freedom not to have one's personal information disclosed to a third party without permission (73). This implies a right to the effective protection of personal data against abuse and (in particular) illegal access. Additional protection is ensured by Article 35 of the Constitution on the right of all persons to be secure in their homes, papers and effects, which requires from public authorities to obtain a court warrant issued for "adequate cause" (74) in all cases of "searches and seizures". In its judgment of 15 March 2017 (GPS case), the Supreme Court has clarified that this warrant requirement applies whenever the government invades ("enters into") the private sphere in a way that suppresses the individual's will and thus by means of a "compulsory investigation". A judge may only issue such warrant based on a concrete suspicion of crimes, i.e. when provided with documentary evidence based on which the person concerned by the investigation can be considered as having committed a criminal offence (75). Consequently, Japanese authorities have no legal authority to collect personal information by compulsory means in situations where no violation of the law has yet occurred (76), for example in order to prevent a crime or other security threat (as is the case for investigations on grounds of national security).
Under the reservation of law principle, any data collection as part of a coercive investigation must be specifically authorised by law (as reflected, for instance, in Article 197(1) of the Code of Criminal Procedure ("CCP") regarding the compulsory collection of information for the purposes of a criminal investigation). This requirement applies also to access to electronic information.
Importantly, Article 21(2) of the Constitution guarantees the secrecy of all means of communication, with limitations only allowed by legislation on public interest grounds. Article 4 of the Telecommunications Business Act, according to which the secrecy of communications handled by a telecommunications carrier shall not be violated, implements this confidentiality requirement at the level of statutory law. This has been interpreted as prohibiting the disclosure of communications information, except with the consent of users or if based on one of the explicit exemptions from criminal liability under the Penal Code (77).
The Constitution also guarantees the right of access to the courts (Article 32) and the right to sue the State for redress in the case where an individual has suffered damage through the illegal act of a public official (Article 17).
As regards specifically the right to data protection, Chapter III, Sections 1, 2 and 3 of the APPI lays down general principles covering all sectors, including the public sector. In particular, Article 3 of the APPI provides that all personal information must be handled in accordance with the principle of respect for the personality of individuals. Once personal information, including as part of electronic records, has been collected ("obtained") by public authorities (78), its handling is governed by the Act on the Protection of Personal Information held by Administrative Organs ("APPIHAO") (79). This includes in principle (80) also the processing of personal information for criminal law enforcement or national security purposes. Among others, the APPIHAO provides that public authorities: (i) may only retain personal information to the extent this is necessary for carrying out their duties; (ii) shall not use such information for an "unjust" purpose or disclose it to a third person without justification; (iii) shall specify the purpose and not change that purpose beyond what can reasonably be considered as relevant for the original purpose (purpose limitation); (iv) shall in principle not use or provide a third person with the retained personal information for other purposes and, if they consider this necessary, impose restrictions on the purpose or method of use by third parties; (v) shall endeavour to ensure the correctness of the information (data quality); (vi) shall take the necessary measures for the proper management of the information and to prevent leakage, loss or damage (data security); and (vii) shall endeavour to properly and expeditiously process any complaints regarding the processing of the information (81).