This practice of uploading fake torrents is sometimes carried out by anti-infringement organisations as an attempt to prevent the peer-to-peer (P2P) sharing of copyrighted content, and to gather the IP addresses of downloaders.
The attacker inserts a large amount of invalid information into the index to prevent users from finding the correct resource.
[5] When a user attempts to download the corrupted content, the server will fail to establish a connection due to the large volume of invalid information.
[4] Some companies that disrupt P2P file sharing on behalf of content providers create their own software in order to launch attacks.
The protocol identifies a peer with its endpoint address while the file index format is changed to incorporate a digital signature.
Using identity based signatures, the system enables each peer to identify infringing users without the need for communication with a central authority.
If all legitimate users simply deny download requests from known infringers, the latter can usually accumulate clean chunks from colluders (paid peers who share content with others without authorization).
However, this method of content poisoning forces illegitimate users to discard even clean chunks, prolonging their download time.
[7] Voluntary Collective Licensing and the Open Music Model are theoretical systems where users pay a subscription fee for access to a file-sharing network, and are able to legally download and distribute copyright content.
Content providers and copyright holders may decide that the financial outlay is not worth the end result of their efforts.
These measures must be combined in order to have a significant impact on illegal peer-to-peer filesharing using BitTorrent protocols and Torrent files.
[13][14] In 2005 the Finnish anti-infringement organisation Viralg claimed that their software, which uses a similar approach to spoofing, could be used to bring an end to illegal P2P file sharing.
[17] In some jurisdictions, there were concerns that content providers and copyright holders engaging in poisoning activities may be held liable for damages to users' computers.
In the US in 2002, Representative Howard Berman proposed the Peer To Peer Piracy Prevention Act, which would have granted immunity to copyright holders for taking steps to prevent the illegal distribution of their content (i.e. poisoning activities) on P2P networks, as long as they did not go as far as to harm the files stored on a P2P user's computer.
The Nopir-B worm, which originated in France, poses as a DVD copying program and deletes all the mp3 files on a user's computer, regardless of whether or not they were legally obtained.
[13][26] On 19 October 2007 Associated Press (AP) released information accusing the broadband service provider Comcast of "hindering" P2P file sharing traffic.