Leeches are worms that predominantly suck blood and feed on blood from vertebrate and invertebrate animals. Historically, leeches were widely used for medical purposes in Greece and India to remove blood from patients. Modernly, in the internet world however, web administrators and website owners associate leeches with more subtle ends, rather than the sucking of blood, merely the sucking of computing resources. This historical association is modernly used to associate users across the internet who use resources on a network without paying for them or giving anything back to the network.
On a torrent network a leecher is someone who downloads files without adequately contributing to the network, in a meaningful way – typically by disconnecting from the network as soon as he/she has completely downloaded the file. On other networks, a leecher is someone who benefits from the network or gathers information from the network and offers nothing in return. In economic terms, such users are called free riders. For example, a member of a labor union who does not pay any dues but benefits from the efforts of the union.
As a website owner, you should be concerned about leechers using your resources such as disk space, bandwidth and other computing resources such as processing power or memory. This may occur when users that are authorized by you to use the website use it in a manner that is not authorized or intended by you. For example, a university may offer its students a cloud storage space for educational purposes, and some students may maliciously use such storage space to store movies or mp3 files, which is not necessarily illegal or wrong – but is not the intended use of the resource offered to the students.
This may also occur in a small or medium business, where employees are offered storage space on the network to store the data they need, so that they can access it from multiple locations through the internet – but the employees may end up using the storage space for completely unrelated purposes, such as to store personal information and files. Users may also end up sharing the login information with other people and allow them to use those resources for unintended uses.
As a website owner, depending on whether your resources are scarce and based on the cost benefit of having such leechers, you may want to terminate such leechers. The next obvious question that arises is, how you would identify such leechers, and how you would terminate them. Obviously it is not feasible to individually eliminate each user and verify each user, but there ought to be a system to identify usage patterns and alert you when there is a risk of leechers being on your network.
Many popular web hosting interface providers offer leech protection, and it is widely used in the industry to prevent leeching activity. Mr. Ruzbeh Raja a web administrator at a popular web hosting company said that “Preventing leechers is a priority for many website owners and, indeed widely used by our clients to prevent waste of resources”. Mr. Raja further said that users being offered an unlimited web hosting plan in particular should be concerned about leechers given that they do not have a particular set limit of the resources they can use, he said that this would cause them to run the risk of being caught as abusing their account as a whole.