Peer-to-Peer File Sharing and Copyright Law: A Primer for Developers

The future of peer-to-peer file-sharing and related technologies is entwined, for better or worse, with copyright law. This paper aims to present a layperson's introduction to the copyright law principles most pertinent to peer-to-peer developers, including contributory and vicarious liability principles and potential legal defenses. After describing the current shape of the law, the paper concludes with twelve specific strategies that peer-to-peer developers can undertake to reduce their copyright vulnerabilities. 1 What This Is, and Who Should Read It The future of peer-to-peer file-sharing and related technologies is entwined, for better or worse, with copyright law. If the early legal skirmishes yield any lesson for P2P developers, it is that an appreciation of the legal environment should be part of any development effort from the beginning, rather than bolted on at the end. This piece is meant as a general explanation of the U.S. copyright law principles most relevant to P2P file-sharing technologies. It is aimed primarily at: Developers of core P2P file-sharing technology, such as the underlying protocols, platform tools, and specific client implementations; and Developers of ancillary services that depend upon or add value to P2P filesharing networks, such as providers of search, security, metadata aggregation,