Procedures for Identifying Authors under Japanese Law

In Japan, there are various legal procedures available to identify the authors of defamatory online posts and combat cyber defamation. As legal professionals, we employ these procedures selectively and in combination to achieve author identification. While providing a comprehensive explanation on this page is challenging due to the highly specialized nature of these procedures, we will provide an overview.

• A: Request for Disclosure (Provisional Disposition)

  This expedited interim measure allows us to request website operators or hosting server administrators to disclose the IP address of the poster, without resorting to formal litigation. However, it is important to note that some websites may provide IP address disclosure voluntarily through informal negotiations without the need for this procedure. Making the right judgment in such cases requires the experience and expertise of knowledgeable lawyers.

• B: Prohibit Deletion of Information

  By analyzing the disclosed IP address obtained through Procedure A, it is possible to identify the internet service provider (ISP) used by the anonymous user. In Procedure C, it is crucial to request the ISP not to delete the sender information (log data related to the user’s internet connection) to preserve evidence.

• C: Request for Disclosure (Lawsuit)

  This procedure involves suing the identified ISP as a defendant to seek the disclosure of the anonymous user’s address and name. In the case of websites where the anonymous user registered a phone number, this procedure can be used against the website operator to request the disclosure of that phone number. Prompt interim measures cannot be used in this procedure, and formal litigation is required according to Japanese legal precedents.

• D: Disclosure Order (the 2022 Amendment)

  This newly introduced legal framework combines Procedures A, B, and C into a single procedure, enabling the implementation of all steps (A, B, and C) within a shorter timeframe. This procedure utilizes an expedited mechanism. Currently, this procedure is considered the general principle for author identification. However, there are exceptions, such as websites where only a phone number is registered without an IP address or cases where disclosure of the IP address can be achieved through voluntary negotiations. The expertise and know-how of legal professionals are essential in handling these exceptions.

• E: Inquiry Procedure through Bar Association

  In cases where the phone number of the poster becomes known during the aforementioned procedures, it is necessary to request the disclosure of the address or name of the person using that phone number from the telecommunications carrier. In Japan, mobile phone carriers have a practice of providing information disclosure when a lawyer makes a proper inquiry through their affiliated bar association.