Leecher (computing)


In computing and specifically in Internet slang, a leech is one who benefits, usually deliberately, from others' information or effort but does not offer anything in return, or makes only token offerings in an attempt to avoid being called a leech. In economics, this type of behavior is called "free riding" and is associated with the free rider problem. The term originated in the bulletin board system era, when it referred to users that would download files and upload nothing in return.
Depending on context, leeching does not necessarily refer to illegal use of computer resources, but often instead to greedy use according to etiquette: to wit, using too much of what is freely given without contributing a reasonable amount back to the community that provides it. The word is also used without any pejorative connotations, simply meaning to download large sets of information: for example the offline reader , the Usenet newsreader NewsLeecher, the audio recording software , or , a utility to download attachments from POP3 mailboxes.
The name derives from the leech, an animal that sucks blood and then tries to leave unnoticed. Other terms are used, such as "freeloader", "mooch" and "sponge", but leech is the most commonly used.

Examples

In games the term "leech" is given to someone who avoids confrontation and sits out while another player fights and gains experience for the person, or "leecher", who is avoiding confrontation.
Amongst users of the BitTorrent file distribution protocol and common P2P networks, such as the eDonkey network or Gnutella2, a leech is a user who disconnects as soon as they have a complete copy of a particular file, while minimizing or completely suppressing data upload.
However, on most BitTorrent tracker sites, the term leecher is used for all users who are not seeders. As BitTorrent clients usually begin to upload files almost as soon as they have started to download them, such users are usually not freeloaders. Therefore, this kind of leeching is considered to be a legitimate practice. Reaching an upload/download ratio of 1:1 in a BitTorrent client is considered a minimum in the etiquette of that network. In the terminology of these BitTorrent sites, a leech becomes a seeder when they finished downloading and continues to run the client. They will remain a seeder until the file is removed or destroyed.
The so-called bad leechers are those running specially modified clients which avoid uploading data. This has led to the development of a multitude of technologies to ban such misbehaving clients. For example, on BitTorrent, most private trackers do keep track of the amount of data a client uploads or downloads to avoid leeching, while on real P2P networks systems like DLP or uploader rewarding have been brought in place. Note that BitTorrent is not a P2P network, it is only a P2P file distribution system.
Leeching is often seen as a threat to peer-to-peer sharing and as the direct opposite of the practice of seeding. But with rising downloads, uploads are still guaranteed, although few contributors in the system account for most services.