Copyright Date
Case

May 16, 2024

Court

2023 (Ne) 10110

Intellectual Property High
Court, First Division

number- A case in which, with respect to the sharing of a reproduction of a video, which is a
copyright work, on a BitTorrent network, the court granted the request for disclosureof sender identification information by the copyright owner, finding that theidentification information of senders of the "handshake communications" between
each peer and the monitoring software was the "sender identification information,
relative to violating the person's rights" under Article 5, paragraph (1) of the Act
on the Limitation of Liability of Specified Telecommunications Service Providers
for Damages and the Right to Demand Disclosure of Sender Identification
Information.
Case type: Disclosure of Identification Information of Senders
Result: Reversal of prior instance judgment, granted
References: Article 2, paragraph (1), item (ix)-5 of the Copyright Act, Article 5,paragraph (1) of the Act on the Limitation of Liability of Specified
Telecommunications Service Providers for Damages and the Right to Demand
Disclosure of Sender Identification Information
Judgment in prior instance: Tokyo District Court, 2023 (Wa) 70029 dated October 27,
2023
Summary of the Judgment
1. This is a case in which X requested from Y, a telecommunications service provider,the disclosure of information on senders (the "Sender Identification Information")pursuant to Article 5, paragraph (1) of the Act on the Limitation of Liability ofSpecified Telecommunications Service Providers for Damages and the Right toDemand Disclosure of Sender Identification Information (hereinafter referred to as
the "Act"), on the allegation that with respect to a video, which is X's copyrighted
work (the "Video"), its right to make available for transmission was obviously
infringed as unknown users (the "Unknown Users") made a reproduction (the"Reproduction File") of the Video available for transmission.
2. In the judgment in prior instance, the court dismissed the Appellant's claim in its
entirety, holding that it could not be found that "it is obvious that the rights of theperson demanding the disclosure have been violated" (Article 5, paragraph (1), item(i) of the Act) with respect to X and that the Sender Identification Information wasinot considered as the "sender identification information, relative to violating theperson's rights" (Article 5, paragraph (1) of the Act). The Appellant appealed against
this judgment.
3. In this judgment, the court held as follows in summary, revoking the judgment inprior instance and granting X's claim.
(1) Whether "it is obvious that the rights of the person demanding the disclosure havebeen violated"
BitTorrent is a protocol wherein a terminal computer device acting as a peer
participates in a network dedicated to the specific file for sharing, implements a peer to-peer handshake communication to check other peers' status of performance andpossession of file pieces, sends a request to and receives file pieces from other peers
possessing pieces constituting the aforementioned specific file, or transmits its own
file pieces in response to a request from other peers, so as to finall y obtain thecomplete pieces of the specific file.
Considering the fact that the Reproduction File shared on the BitTorrent network
was copied from the Video, and that the Sender Identification Information is theinformation on senders of the handshake communications between the monitoring
software and individual peers using the IP addresses and port numbers acquired by
the monitoring software in the form of a list of peers sharing the Reproduction File,the peer users can be considered to have made available for transmission the
reproduction of the Video, jointly and in connection with other peer users
respectively before the specific date and time of their handshake transmission.
Therefore, it is obvious that the Appellant's right to make the Video available fortransmission was infringed.
(2) Whether the Sender Identification Information is "sender identification
information, relative to violating the person's rights"
Article 5, paragraph (1) of the Act uses rather inclusive wording: "sender
identification information, relative to violating the person's rights," and provides that"the sender identification information, relative to violating the person's rights "includes specified sender identification information (which is spe cified by Order ofthe Ministry of Internal Affairs and Communications as sender identification
information that relates solely to the violation-related telecommunications). Theseviolation-related

telecommunications

corresponding

tospecifiedsenderidentification information are not specified telecommunications for recording or
inputting violating information. In light of the literal interpretation of the provisions
mentioned above, it is reasonably understood that the "sender identificationii

information, relative to violating the person's rights" is not necessarily limited to
information on senders of specified telecommunications for recording or inputting
violating information.
For file sharing on a BitTorrent network, if the "sender identification information,
relative to violating the person's rights" should be limited to information oncommunications for actual exchange of each file piece, a copyright owner whose
copyright work was shared on a BitTorrent network without authorization would facesignificant burden to enforce their rights as appropriate to the circumstance of
infringement. Such situation would run counter to the purpose of Article 5 of the Act
and Article 23, paragraph (1) of the Copyright Act. Meanwhile, although informationexchanged through handshake communications per se does not constitute an
infringement, handshake communications are for a device of a user acting as a peer
on a BitTorrent network dedicated to sharing the specific file to check other peers'
status of performance and possession of file pieces and to make responses, and theexchange of the relevant file pieces usually takes place after such communications.
If there exists a probability that this act was conducted by the same person as thesender of the information to which the act relates, and if the file in question was
copied from a copyright work of a third party without authorization , handshakecommunications present closer connection with the act of infringement compared toviolation-related communications (as adopted by the 2023 amendment of the Act),
such as communications for log-on. Therefore, even considering the necessity toprotect the sender's privacy, freedom of expression and secrecy of communications,
it would be permissible to grant the demand for disclosure under the requirements
equivalent

to

those

appliedtoinformationonsendersof

specifi ed

telecommunications for transmitting the relevant infringing information.
Given the above, it is reasonable to consider that the Sender Identification
Information falls under the "sender identification information, relative to violating
the person's rights" as prescribed in Article 5, paragraph (1) of the Act.

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Judgement rendered on May 16, 2024
2023 (Ne) 10110, Appeal case of seeking disclosure of identification information of thesenders(Court of prior instance: Tokyo District Court 2023 (Wa) 70029)
Date of conclusion of oral argument: March 12, 2024
Judgment
Appellant: Prestige Inc.
Appellee: SoftBank Corp.
Main text
1. The judgment in prior instance shall be revoked.
2. The Appellee shall disclose the information specified in the attached List of Sender
Identification Information to the Appellant.
3. The court costs for the first and second instances shall be borne by the Appellee.
Facts and reasonsNo. 1 Object of the claim
Same as the main text
No. 2 Outline of the case (Unless particularly noted, the same abbreviatio ns used in
the judgment in prior instance shall be used herein.)
1. Summary of the caseThis is a case in which the Appellant requested from the Appellee, atelecommunications service provider, the disclosure of the pieces of information
specified in the attached List of Sender Identification Information (the "Sender
Identification Information") pursuant to Article 5, paragraph (1) of the Act on the
Limitation of Liability of Specified Telecommunications Service Providers for
Damages and the Right to Demand Disclosure of Sender Identification Information(hereinafter referred to as the "Act"), on the allegation that its copyright (right tomake available for transmission) with respect to a video specified in the List of
Copyright Work attached to the judgment in prior instance (the "Video") was
obviously infringed as unknown users (the "Unknown Users") made a reproduction1

of the Video (the "Reproduction File") available for transmission.
In the judgment in prior instance, the court dismissed the Appellant's claim in its
entirety, holding that it could not be found that "it is obvious that the rights of theperson demanding the disclosure have been violated" (Article 5, paragraph (1), item(i) of the Act) with respect to the Appellant, and that the Send er Identification
Information was not considered as the "sender identification information, relative to
violating the person's rights" (Article 5, paragraph (1) of the Act). The Appellant
appealed against this judgment.
2. Basic facts
The basic facts and issues are as described in No. 2, 2 and 3 of the "Facts andreasons" section (from page 2, line 8 to page 4, line 22) of the judgment in priorinstance and therefore cited herein, except for amending the reference to "Exhibit Ko
4" in page 3, line 25 of the judgment in prior instance to "Exhibit Ko 11."

No. 4 Judgment of this court
1. Issue 1 (whether "it is obvious that the rights of the person demanding thedisclosure have been violated" with respect to the Appellant)(1) According to the basic facts (No. 2, 2 of the "Facts and reasons" section of thejudgment in prior instance cited with an amendment), BitTorrent is a protocol
wherein a terminal computer device acting as a peer participates in a network
dedicated to the specific file for sharing, implements a peer-to-peer handshakecommunication to check other peers' status of performance and possession of filepieces, sends a request for and receives file pieces from other peers possessing pieces
constituting the aforementioned specific file, or transmits its own file pieces in
response to a request from other peers, so as to finally obtain the complete pieces ofthe specific file.
From the evidence (Exhibits Ko 5 through 9 and 11) and the entire import of oral
arguments, the following facts are found: [i] the Reproduction File shared on the
BitTorrent network

was copied from the Video; [ii] the combination of the IP

addresses and port numbers specified in the List of the Video attached to the
judgment in prior instance were acquired by the monitoring software in question

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("Monitoring Software") through a tracker in the form of a list of peers sharing the
Reproduction File; and [iii] the dates and times of transmissions specified in the same
list indicate the respective dates and times of responses made by individual peers
respectively assigned with the aforementioned IP addresses and port numbers
through handshake communications with the Monitoring Software.
Then, it follows from the above that each peer user made available fortransmission the pieces of the Reproduction File copied from the Video, upon therequest from unspecified persons and for the purpose of enabling these persons to
directly receive the pieces, respectively before the specific date and time of theirtransmission. In other words, it is understood that these peer users made available
for transmission, jointly and in connection with other peer users, the Reproduction
File copied from the Video, upon the request from unspecified persons and for the
purpose of enabling them to directly receive the pieces. This amounts to an act ofrecording the pieces , which are segmented pieces of information of the Reproduction
File, in a recording media for public transmission installed on a peer device which is
an automatic public transmission server connected to a public telecommunications
network (Article 2, paragraph (1), item (ix)-5, (a) of the Copyright Act), or
connecting a peer device, which is an automatic public transmission server storing
the Reproduction File acquired by means other than a BitTorrent network, in suchrecording media for automatic public transmission to a public telecommunications
network (Article 2, paragraph (1), item (ix)-5, (b) of the Copyright Act). Therefore,
it is obvious that the Appellant's right to make the Video available for transmission
was infringed.
(2) The Appellee argues that in order to find an obvious infringement of a right tomake the Video available for transmission by those peer users, each peer user isrequired to possess 100% or equivalent percentage of the complete pieces . However,as stated in (1) above, peers participating in a BitTorrent network possess andexchange their respective portions of file pieces for sharing, enabling each of themto finally acquire the complete pieces constituting the relevant file. Therefore, eachpeer user can be considered to make the relevant file available for automatic public
transmission, jointly and in connection with other peer users. A peer that responded3

to a handshake communication is deemed to have indicated that it possesses pieces
that constitute part of the relevant file and stores them in its device and is ready toshare them with other peers upon their request. Therefore, each peer can beconsidered to have conducted an act of making the file available for transmission
jointly with other peers, without regard to the number of pieces it possesses.
Therefore, the Appellee's argument in this respect is found to be unacceptable.
2. Issue 2 (whether the Sender Identification Information is "sender identification
information, relative to violating the person's rights")(1) As discussed in 1. (1) above, the communications specified by the IP addresses,
port numbers and transmission dates and times set out in the List of the Video
attached to the judgment in prior instance are the communications made in responseto the handshake communications between the peers and the Monitoring Software,
not the communications for exchanging the pieces of the Reproduction File withother peers or for connecting the devices recording the Reproduction File to the
network. In this case, the issue arises as to whether information on senders of such
communications (the "Sender Identification Information") falls under the "sender
identification information, relative to violating the person's rights" as prescribed in
Article 5, paragraph (1) of the Act.
(2) To discuss this issue, with respect to information on senders for which disclosure
can be requested, Article 5, paragraph (1) of the Act uses rather i nclusive wording:"sender identification information, relative to violating the person's rights," and also
provides that the "sender identification information, relative to violating the person's
rights" includes specified sender identification information (which is specified by
Order of the Ministry of Internal Affairs and Communications as sender
identification

information

thatrelatessolelytotheviolation-related

telecommunications), but the violation-related telecommunications corresponding to
specified sender identification information are not specified telecommunications forrecording or inputting violating information. In light of the literal interpretation of
the provisions mentioned above, it is reasonably understood that the "sender
identification information, relative to violating the person's rights" is not necessarily
limited to information on senders of specified telecommunications for recording or

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inputting violating information.
Meanwhile, the purpose of Article 5 of the Act is understoo d as to enable theidentification of the infringer and to ensure remedies for the victim by allowing thevictim of the infringement of their right due to the dissemination of information by
way of specified telecommunications to demand the disclosure of information on
senders from a specified telecommunications service provider that uses specified
telecommunications facilities to be used for the specified telecommunications, understrict requirements in consideration of the sender's privacy, freedom of expression
and secrecy of communications, in light of the characteristics of information
dissemination by means of specified telecommunications that are different from those
of

any

other

information

disseminationmeans,

namely,thatspecifi ed

telecommunications can facilitate the infringement of others' rights, that the resulting
damage can be aggravated without limit due to the high transmissibility of
information, and that the anonymous dissemination of information may make it
impossible to even identify the infringer and may make it difficult to recover damage(see 2009 (Ju) 1049, judgment of the First Petty Bench of the Supreme Court of April
8, 2010, Minshu, Vol. 64, No. 3, at 676). Through the amendment of the Act by Act
No. 27 of 2021, a right to demand the disclosure of specified sender identification
information was newly created with stricter requirements as compared with those fora right to demand the disclosure of sender identification information other thanspecified sender identification information. The purport of the stricter requirements
is understood as to allow the disclosure only to the extent necessary for identifying
the sender of infringing information. This is because although it is found necessary
to allow the disclosure of information on senders of infringement-related
communications, such as communications for log-on or log-out from SNS, etc., suchinformation per se is not infringing and it is highly necessary to protect the sender 's
privacy, freedom of expression and secrecy of communications.
Further, Article 23, paragraph (1) of the Copyright Act provides that theexclusive right to transmit to the public held by the author of a work includes theright to make the work available for transmission, if the work is to be transmitted tothe public via automatic public transmission. The purpose of this provision is5understood as enabling the enforcement of copyright by defining an act that takes
place before the execution of an automatic public transmission as an act of "making
available for transmission," in consideration of the fact that it is practically difficult
for a copyright owner to check and identify individual senders, time, contents andother attributes of automatic public transmissions on the internet and other networks.
As file sharing by BitTorrent is completed piece-by-piece by the exchange ofsegmented pieces of a file among participating peers on a network dedicated to thespecific file, it can be presumed that data exchange therefor would involve quite alarge amount of traffic. If the "sender identification information, relative to violating
the person's rights" should be limited to information on communications for actual
exchange of each file piece, a copyright owner whose copyright work was shared ona BitTorrent network without authorization would face significant burden toinvestigate every communication on the network in order to enforce their rights asappropriate to the circumstance of infringement. This situation would run counter tothe purpose of Article 5 of the Act as mentioned above, namely, to enable theidentification of the infringer to ensure remedies for victims, or the purpose of Article
23, paragraph (1) of the Copyright Act, namely, to enable the enforcement of
copyright for an act that takes place before an automatic public transmission.
Meanwhile, although information exchanged through handshake communications
per se does not constitute an infringement, handshake communications are for adevice of a user acting as a peer on a BitTorrent network dedicated to sharing thespecific file to check other peers' status of performance and possession of file pieces
and to make responses, and the exchange of the relevant file pieces usually takes
place after such communications. Thus, if a handshake communication is made, thatmeans that the relevant peer user made the specific file, at least partially, available
for transmission before the date and time of such communication. If there exists a
probability that this act was conducted by the same person as the sender of theinformation to which the act relates, and if the file in question was copied from a
copyright work of a third party without authorization, handshake communications
present closer connection with the act of infringement compared to viol ation-related
communications, such as communications for log-on. Therefore, even considering

6the necessity to protect the sender's privacy, freedom of expression and secrecy ofcommunications, it would be permissible to grant the demand for disclosure unde r
the requirements equivalent to those applied to information on senders of specifi ed
telecommunications for transmitting the relevant infringing information.
Given the above, it is reasonable to consider that the Sender Identification
Information falls under the "sender identification information, relative to violating
the person's rights" as prescribed in Article 5, paragraph (1) of the Act.
(3) The Appellee argues that communications subject to the right to request
disclosure pursuant to Article 5, paragraph (1) of the Act should be limited to thecommunications that actually caused the dissemination of infringing information.
However, as stated in (2) above, it is reasonable to understand that the "sender
identification information, relative to violating the person's rights" for which
disclosure can be requested under the Act is not limited to information on senders ofspecified telecommunications for recording or inputting infringing information.
Therefore, the Appellee's argument in this respect is found to be unacceptable.
The Appellee argues that the handshake communications in question are notspecified telecommunications as they are merely one-on-one communications
between the Monitoring Software and individual peers, not involving thetransmission of any file pieces. However, as handshake communications by
individual peers take place between a large number of unspecified other peers on thesame BitTorrent network, it can be considered as communications intended to bereceived by unspecified persons. In addition, communications not transmitting any
file pieces are not necessarily excluded from the definition of specifi ed
telecommunications. Therefore, the Appellee's argument is found to be unacceptable.
3. Issue 3 (whether the Appellant has "legitimate grounds to receive disclosure" ofthe sender identification information)
From the entire import of oral arguments, the court finds that the Appellant
intends to claim compensation for damages arising from the infringement of its
copyright in the Video against the Unknown Users. As there are no specificcircumstances, such as that the Appellant has already identified the respective
Unknown Users, the Appellant has legitimate grounds to receive disclosure of the7Sender Identification Information.
4. Issue 4 (whether the Appellee possesses the Sender Identification Information)
The evidence (Exhibit Ko 5) indicates that the Unknown Users were assignedwith IP addresses specified in the column of IP addresses in the List of the Video
attached to the judgment in prior instance from the Appellee at the dates and times
specified in the same list. From this evidence, it is presumed that the Appellee
possesses the Sender Identification Information, and there is no evidence to rebut
this presumption.
5. Conclusion
From the above findings, the Appellant's claim is well-grounded and therefore
should be granted. The judgment in prior instance dismissing the Appellant's claim
is groundless and the appeal is well-grounded. Therefore, this court revokes the
judgment in prior instance, grants the Appellant's claim and renders the judgment as
described in the main text.
Although the Appellant requested a declaration of provisional execution in the
petition for appeal, it is not appropriate to grant the provisional execution withrespect to the judicial decision to grant the disclosure of Sender Identification
Information, and it is found to be unnecessary to issue a declaration of provisional
execution for the judicial decision on the allocation of court costs. Therefore, thecourt does not issue the declaration of provisional execution.

Intellectual Property High Court, First Division
Presiding Judge: HONDA Tomonari
Judge: TOYAMA Atsushi
Judge: AMANO Kenji

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(Attachment)

List of Sender Identification Information

The following categories of information on users to which the IP addresses specified
in the List of the Video attached to the judgment in prior instance were assigned by
the Appellee, as at around the times of transmission as set forth in the same List:(1) Name(2) Address(3) Email address

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