- Proxy Caching: Proxy caching occurs at the server level, rather than at the end user’s
computer level. Specifically, a copy of material from an original source is stored on a
server other than the original server. For example, an OSP such as AOL may store on
its own server for a certain period of time Web pages that have been previously
requested by AOL users. When another user subsequently requests a page previously
stored, AOL may download the page from its own server, rather than fetching the
page from the original source server.
The use of caching on the Internet stems from at least three reasons: to overcome
transmission bandwidth limitations, to load balance serving up web pages (such as through
search engines) or distributing other content in high demand through multiple sources, and to
preserve archival versions of web pages for use in the event that web sites are removed or go
down temporarily.
Caching presents difficult copyright issues on a number of fronts. Because caching
involves the making of copies, it presents an obvious problem of potential infringement of the
right of reproduction. In addition, proxy caching may give rise to infringement of the rights of
public distribution, public display, public performance, and digital performance, since copies of
copyrighted works may be further distributed and displayed or performed from the cache server
to members of the public. Under the WIPO treaties, caching may also infringe the new rights of
transmission and access. Because the situs of infringements of these rights under the WIPO
treaties is most likely the server, caching may give rise to infringements at every proxy server.
Large OSPs may have proxy servers at many sites around the globe.
- The Detriments of Caching
From a legal perspective, because caching has obvious technical benefits in getting
information from the Internet to a user faster, one might assume that a copyright owner who has
placed information on the Internet and desires such information to reach end users as
expeditiously as possible would have no incentive to assert its copyright rights against
caching.^1524 In legal terms, one might be tempted to conclude that caching will fall within the
fair use or implied license doctrines. However, the legal analysis is complex, because caching
carries with it a number of potential detriments to the owner of the copyrighted material:^1525
- Loss of Version Control: Caching interferes with the ability of a website operator to
control what version of information is delivered to the end user.^1526 For example, a
website may have been substantially improved, yet an old version of material from
the site may reside on the proxy server of the end user’s OSP. Many end users may
(^1524) Indeed, in a poll taken during 1997 by Interactive PR & Marketing News, 82% of respondents answered “no” to
the question, “Do you feel that caching of content of Web sites or online service providers constitutes
infringement?” Interactive PR & Marketing News, Vol. 4, No. 28 (Aug. 8, 1997), at 1.
(^1525) In addition to the detriments noted to the copyright owner, caching can give rise to potential liability on the part
of the caching entity. For example, if an original site contains defamatory material, the caching entity may be
deemed to have “republished” that defamatory information through the caching mechanism.
(^1526) Eric Schlachter, “Caching on the Internet,” Cyberspace Lawyer, Oct. 1996, at 2, 3.