Japanese BitTorrent users who believed they were simply downloading adult videos for free are increasingly finding themselves facing court notices and settlement demands worth hundreds of thousands of yen as copyright holders step up efforts to identify alleged infringers.
One Tokyo man in his 40s, who is self-employed, said he began using file-sharing software after reading about it online.
He would start downloading adult videos before going to bed and turn the software off the following morning, giving him access to large numbers of videos without paying.
That changed in May, when a letter arrived at his home stating that a court had approved the disclosure of information identifying him, including his name, address and telephone number.
Around 20 days later, another letter arrived from a lawyer representing a video production company. The lawyer demanded 500,000 yen and warned that civil or criminal action could follow if he refused to pay.
“My first thought was that it had to be some kind of scam,” the man said.
After examining the documents, however, he concluded they appeared genuine. The notice referred to rights covering the online transmission of copyrighted material, leading him to believe his use of file-sharing software was behind the claim.
“I decided I had better treat it as genuine and get proper advice,” he said, adding that consulting a lawyer seemed like the safest option.
The number of such cases has been rising sharply in Japan. Data from the Tokyo District Court showed applications seeking orders to disclose identifying information through its intellectual property division increased from 814 in 2023 to 2,454 in 2024 and 5,320 in 2025.
A Communications Ministry survey also found that 95.6% of disclosure requests received by major internet service providers and other organisations in 2024 involved alleged copyright infringement relating to adult videos.
Video production companies have developed systems to identify the IP addresses of people suspected of sharing copyrighted material through file-sharing software, according to records from similar lawsuits.
Once an IP address is identified, copyright holders can seek a court order requiring an internet service provider to disclose information about the user before pursuing settlement payments or damages.
The Communications Ministry has warned people against casually using file-sharing software as disputes over such demands continue.
BitTorrent and similar platforms use peer-to-peer technology, allowing computers to exchange files directly rather than downloading them from a central server. Importantly, users may also automatically upload portions of a file to others while downloading it themselves.
This means people who believe they are only downloading content could also be distributing copyrighted material to other users.
The Tokyo man sought legal advice from a law firm he found through online reviews. His lawyer told him there was no need to panic or immediately pay the 500,000 yen being demanded.
Because the case involved adult videos, the man said he found it difficult to tell his family about the situation.
“Even when I was at work, it would suddenly pop into my mind,” he said.
He said the stress began affecting his daily life, but his anxiety eased after his lawyer took over communication with the other party. Negotiations are now underway to reduce the amount being sought.
“I’m glad I didn’t just ignore it and instead went to someone for advice,” he said.
The man acknowledged that he had been aware there was something questionable about his actions.
“I really wish I had never started,” he said. “I won’t be using it again.”
Lawyer Izumi Toda, who represents video production companies and other copyright holders, warned against online advice suggesting people could simply ignore settlement demands and wait for the statute of limitations to expire.
“That is not something people should assume they can get away with,” he said, noting that rights holders could potentially pursue criminal complaints if recipients refused to respond.
Toda said BitTorrent users generally need to install and configure the software, which could lead rights holders to view the alleged infringement as deliberate rather than accidental.
“Using it requires a certain amount of knowledge and preparation,” he said. “That can lead rights holders to view the infringement as more serious.”
However, Toda said copyright holders did not necessarily want to take every case to court or pursue criminal penalties.
“From their point of view, these people could also have been paying customers,” he said, adding that there could be room to reduce settlement amounts when individuals respond sincerely and there are circumstances worth considering.
Lawyer Yasufumi Sasanami, who has advised more than 1,000 people facing similar claims, including the Tokyo man, said production companies had developed systems that allowed them to pursue such cases on a large scale.
“They now have an established process for making these claims in volume, and it has become a substantial source of income,” he said.
Sasanami also warned that settling one claim may not necessarily end the matter, as users who downloaded multiple titles from different companies could receive further demands relating to other videos.
“The sums being sought for individual titles are high, and I don’t think the level of liability matches the conduct involved,” he said, calling for courts to provide clearer standards on what constitutes an appropriate level of compensation.
