Author: Benjamin Edelman

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Web Sites Sharing IP Addresses: Prevalence and Significance

Web Sites Sharing IP Addresses: Prevalence and Significance. (September 2013)

More than 87% of active domain names are found to share their IP addresses (i.e. their web servers) with one or more additional domains, and more than two third of active domain names share their addresses with fifty or more additional domains. While this IP sharing is typically transparent to ordinary users, it causes complications for those who seek to filter the Internet, restrict users’ ability to access certain controversial content on the basis of the IP address used to host that content. With so many sites sharing IP addresses, IP-based filtering efforts are bound to produce “overblocking” — accidental and often unanticipated denial of access to web sites that abide by the stated filtering rules.

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Large-Scale Registration of Domains with Typographical Errors

Large-Scale Registration of Domains with Typographical Errors. (January 2003)

The author reports more than eight thousand domains that consist of minor variations on the addresses of well-known web sites, reflecting typographical errors often made by Internet users manually typing these addresses into their web browsers. Although the majority of these domain names are variations of sites frequently used by children, and although their domain names do not suggest the presence of sexually-explicit content, more than 90% offer extensive sexually-explicit content. In addition, these domains are presented in a way that temporarily disables a browser’s Back and Exit commands, preventing users from exiting easily. Most or all of the domains are registered to an individual previously enjoined by the FTC from operating domains that are typographic variations on famous names, and these domains remain operational subsequent to an injunction ordering their suspension.

 

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Empirical Analysis of Internet Filtering in China with Jonathan Zittrain

Empirical Analysis of Internet Filtering in China – full article.

The authors are collecting data on the methods, scope, and depth of selective barriers to Internet access through Chinese networks. Tests from May 2002 through November 2002 indicate at least four distinct and independently operable methods of Internet filtering, with a documentable leap in filtering sophistication beginning in September 2002. The authors document thousands of sites rendered inaccessible using the most common and longstanding filtering practice. These sites were found through connections to the Internet by telephone dial-up link and through proxy servers in China. Once so connected, the authors attempted to access approximately two hundred thousand web sites. The authors tracked 19,032 web sites that were inaccessible from China on multiple occasions while remaining accessible from the United States. Such sites contained information about news, politics, health, commerce, and entertainment. See highlights of blocked pages. The authors conclude (1) that the Chinese government maintains an active interest in preventing users from viewing certain web content, both sexually explicit and non-sexually explicit; (2) that it has managed to configure overlapping nationwide systems to effectively — if at times irregularly — block such content from users who do not regularly seek to circumvent such blocking; and (3) that such blocking systems are becoming more refined even as they are likely more labor- and technology-intensive to maintain than cruder predecessors.

Revised and published as Internet Filtering in China (IEEE Internet Computing 2003).