Internet Filtering in China
IEEE Internet Computing, (March 2003)Abstract
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. 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.
