Researchers say they’ve uncovered two interesting patterns about peer-to-peer file sharing of movies, music, and more.
The team analyzed an unprecedented amount of data on users of BitTorrent, a popular file-sharing system. Here’s what they discovered:
- Most BitTorrent users are content specialists—sharing music but not movies, for example.
- Users in countries with similar economies tend to download similar types of content—those living in poorer countries such as Lithuania and Spain, for example, download primarily large files, such as movies.
“Looking into this world of internet traffic, we see a close interaction between computing systems and our everyday lives,” says Luís A. Nunes Amaral, a professor of chemical and biological engineering at Northwestern University and a senior author of the study.
“People in a given country display preferences for certain content—content that might not be readily available because of an authoritarian government or inferior communication infrastructure.
“This study can provide a great deal of insight into how things are working in a country.”
Amaral and Fabián E. Bustamante, professor of electrical engineering and computer science, also at McCormick, co-led the research team with colleagues from Universitat Rovira i Virgili in Spain.
Content Connects Users
Their study, published in the Proceedings of the National Academy of Sciences, reports BitTorrent users in countries with a small gross domestic product (GDP) per capita were more likely to share large files, such as high-definition movies, than users in countries with a large GDP per capita, where small files such as music were shared.
Also, more than 50 percent of users’ downloaded content fell into their top two downloaded content types, putting them in the content specialist, not generalist, category.
“Our study serves as a window on society as a whole,” Bustamante says. “It was very interesting to see the separations between users based purely on content. Individuals tend to interact only with others who are interested in the same content.”
How BitTorrent Works
One goal of decentralized peer-to-peer file sharing is to make communication on the Internet more efficient. (In certain parts of the world, BitTorrent users are responsible for up to one-third of the total internet traffic.)
The BitTorrent protocol enables users to share large data files even when they don’t have access to broadband connections, which often is the case in rural areas or less developed countries.
BitTorrent breaks files into smaller pieces that can be shared quickly and easily from home computers over networks with lower bandwidth.
The researchers analyzed 10,000 anonymous BitTorrent users from around the world during a typical month using data reported by users of the BitTorrent plugin Ono.
File content types shared by users included small files, music, TV shows, movies, and books. The type of content was easily determined based on file size.
The Ono app, developed by Bustamante and his lab, allows users to improve the performance of BitTorrent while reducing the impact of their traffic on internet network providers. Ono users can give informed consent for research use of their activity, providing a rich source of data on which new studies and projects can be built.
The National Science Foundation supported the research.
*Image of “optical fiber” via Shutterstock