Duhaime's Law Dictionary

Peer-to-Peer File Sharing Definition:

The downloading of a computer file to a user's computer, using software, which then allows the user to make the file available to other users, other "peers".
A form of copyright violation in most jurisdictions by the unauthorized copying and distribution of copyright material, mostly songs in MP3 or other digitized formats.

In MGM Studios, Inc. v. Grokster, Ltd., the Court described the peer-to-peer file sharing system (P2P) as follows:

"... the software can be transferred to the user's computer, or downloaded, from servers operated by Defendants. Once installed, a user may elect to share certain files located on the user's computer, including, for instance, music files, video files, software applications, e-books and text files. When launched on the user's computer, the software automatically connects to a peer-to-peer network. . . and makes any shared files available for transfer to any other user currently connected to the same peer-to-peer network.

"Both the Morpheus and Grokster software provide a range of means through which a user may search through the respective pool of shared files. For instance, a user can select to search only among audio files, and then enter a keyword, title, or artist search. Once a search commences, the software displays a list (or partial list) of users who are currently sharing files that match the search criteria, including data such as the estimated time required to transfer each file. The user may then click on a specific listing to initiate a direct transfer from the source computer to the requesting user's computer. When the transfer is complete, the requesting user and source user have identical copies of the file, and the requesting user may also start sharing the file with others. Multiple transfers to other users (uploads), or from other users (downloads), may occur simultaneously to and from a single user's computer.

"The file-sharing systems in issue in this case, KaZaA and iMesh, work basically on the same principles."


  • MGM Studios, Inc. v. Grokster, Ltd., 259 F. Supp.2d 1029 (C.D. Cal. 2003)
  • BMG Canada Inc. v. John Doe, 2004 FC 488, [2004] 3 F.C.R. 241; and at 239 D.L.R. (4th) 726 • 32 C.P.R. (4th) 64 • 250 F.T.R. 267

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