User behaviors in private BitTorrent communities

Many private BitTorrent communities employ Sharing Ratio Enforcement(SRE) schemes to incentivize users to contribute. It has been demonstratedthat users in private communities are highly dedicated and that they seed muchlonger than users in communities where SRE is not employed. While most pre-vious studies focus on showing the positive effect of user dedication in achievinghigh download speed, in this paper we explore the user behaviors in privatecommunities, we argue the reasons for these behaviors, and we demonstrateboth the positive and the negative effects of these behaviors. We show thatunder SRE, users seed for excessively long times to maintain required sharingratios, but that their seedings are often not very productive (in terms of lowupload speed) and that their long seeding times do not necessarily lead to largeupload amounts. We find that as users evolve in the community, some usersbecome more committed, in terms of increasing ratios between their seedingand leeching times. In the mean time, some users game the system by keepingrisky and low sharing ratios while leeching more often than seeding. Based onthese observations, we analyze strategies that alleviate the negative effects ofthese user behaviors from both the user’s and the community administrator’sperspective