Editing Peer-to-peer (section)

==Social implications==

===Incentivizing resource sharing and cooperation===
[[File:Torrentcomp small.gif|thumb|right|300px|'''The [[BitTorrent]] protocol''': In this animation, the colored bars beneath all of the 7 clients in the upper region above represent the file being shared, with each color representing an individual piece of the file. After the initial pieces transfer from the [[seed (BitTorrent)|seed]] (large system at the bottom), the pieces are individually transferred from client to client. The original seeder only needs to send out one copy of the file for all the clients to receive a copy.]]
Cooperation among a community of participants is key to the continued success of P2P systems aimed at casual human users; these reach their full potential only when large numbers of nodes contribute resources. But in current practice, P2P networks often contain large numbers of users who utilize resources shared by other nodes, but who do not share anything themselves (often referred to as the "freeloader problem").

Freeloading can have a profound impact on the network and in some cases can cause the community to collapse.<ref>Krishnan, R., Smith, M. D., Tang, Z., & Telang, R. (2004, January). The impact of free-riding on peer-to-peer networks. In System Sciences, 2004. Proceedings of the 37th Annual Hawaii International Conference on (pp. 10-pp). IEEE.</ref> In these types of networks "users have natural disincentives to cooperate because cooperation consumes their own resources and may degrade their own performance".<ref name="Feldman, M. 2004, pp. 102-111">Feldman, M., Lai, K., Stoica, I., & Chuang, J. (2004, May). Robust incentive techniques for peer-to-peer networks. In Proceedings of the 5th ACM conference on Electronic commerce (pp. 102-111). ACM.</ref> Studying the social attributes of P2P networks is challenging due to large populations of turnover, asymmetry of interest and zero-cost identity.<ref name="Feldman, M. 2004, pp. 102-111" /> A variety of incentive mechanisms have been implemented to encourage or even force nodes to contribute resources.<ref>{{cite book |last=Vu |first=Quang H. |title=Peer-to-Peer Computing: Principles and Applications |publisher=Springer |year=2010 |isbn=978-3-642-03513-5 |page=172 |display-authors=etal}}</ref><ref name="vu-p2p-principles-p8" />

Some researchers have explored the benefits of enabling virtual communities to self-organize and introduce incentives for resource sharing and cooperation, arguing that the social aspect missing from today's P2P systems should be seen both as a goal and a means for self-organized virtual communities to be built and fostered.<ref>P. Antoniadis and B. Le Grand, "Incentives for resource sharing in self-organized communities: From economics to social psychology," Digital Information Management (ICDIM '07), 2007</ref> Ongoing research efforts for designing effective incentive mechanisms in P2P systems, based on principles from game theory, are beginning to take on a more psychological and information-processing direction.

====Privacy and anonymity====
Some peer-to-peer networks (e.g. [[Freenet]]) place a heavy emphasis on [[privacy]] and [[anonymity]]—that is, ensuring that the contents of communications are hidden from eavesdroppers, and that the identities/locations of the participants are concealed. [[Public key cryptography]] can be used to provide [[encryption]], [[data validation]], authorization, and authentication for data/messages. [[Onion routing]] and other [[mix network]] protocols (e.g. Tarzan) can be used to provide anonymity.<ref>{{cite book |last=Vu |first=Quang H. |title=Peer-to-Peer Computing: Principles and Applications |publisher=Springer |year=2010 |isbn=978-3-642-03513-5 |pages=179–181 |display-authors=etal}}</ref>

Perpetrators of [[live streaming sexual abuse]] and other [[cybercrimes]] have used peer-to-peer platforms to carry out activities with anonymity.<ref>{{cite web|url=https://news.un.org/en/story/2020/03/1058501|title=No country is free from child sexual abuse, exploitation, UN's top rights forum hears|date=March 3, 2020|website=UN News}}</ref>