● Covered by 1 source · 1 reportMedium impact1 neutral
Japanese Authorities Arrest Initial Torrent Seeder Using New Identification Method
Key points
- Masakazu Ono, 56, arrested for being an initial seeder on Nyaa torrent site.
- CODA and Japan Hacker Association identified Ono without monitoring torrent swarm.
- Investigation started in 2021, leading to Ono's arrest in 2024.
- Ono allegedly uploaded nearly a thousand NHK recordings.
Arrest of a Key Torrent Uploader
Masakazu Ono, 56, from Sagamihara, was arrested by Kyoto Prefectural Police following a multi-year investigation. Ono is accused of being an initial seeder on the popular Japanese torrent website Nyaa, specifically for uploading content like the 2026 drama "Midnight Taxi" and nearly a thousand NHK recordings.
New Identification Methodology
The anti-piracy group CODA, with assistance from the Japan Hacker Association (JHA), stated they identified Ono without directly joining or monitoring BitTorrent swarm traffic. CODA indicated their method involved analyzing how data moves through torrent sites, including index and tracker sites. This suggests a departure from traditional methods of identifying torrent users.
Hypothesized Tracking Mechanism
One hypothesis for CODA's method is that they monitored Nyaa trackers to identify IP addresses that consistently appeared as the first to offer complete data sets for specific content. This theory aligns with the duration of the investigation and JHA founder Takayuki Sugiura's past work in decrypting P2P protocols to find original uploaders. Other possibilities include linking Ono's activity through Nyaa logins, cookies, or CDN logs.
Investigation Timeline and Scope
The investigation began in 2021 with CODA's Cross-Border Enforcement Project, aimed at identifying Nyaa uploaders. After three years of data collection with JHA's help, the Kyoto police became involved in 2024, leading to Ono's arrest. Additionally, three "secondary uploaders" from "reach sites" were charged in 2025, indicating a broader enforcement effort against torrent distribution.
✨ This summary was generated by AI from the outlets' reporting listed below. It is not independently verified and may contain errors — check the original sources. How BrevFeed works →
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Reporting from
Japanese authorities arrested Masakazu Ono, an initial seeder on the Nyaa torrent website, after an investigation by anti-piracy group CODA and the Japan Hacker Association. CODA claims it identified Ono without monitoring BitTorrent swarm traffic, suggesting a new method for tracking torrent uploaders. This development indicates a potential shift in anti-piracy enforcement tactics, making it harder for initial content distributors to remain anonymous.