British Telecommunications PLC v. Prodigy Communications Corp.

British Telecommunications PLC (BT) (plaintiff) owned a United States patent (the Sargent patent) naming Desmond Sargent as the sole inventor. Claim 3 of that patent was directed to a “digital storage, retrieval, and display system” that included a ”central computer means” in which were stored “plural blocks of information,” each block comprising “a first portion containing information for display and a second portion containing information not for display.” BT sued Prodigy Communications Corporation (Prodigy) (defendant) for contributory and induced infringement of claims 3, 5, 6, and 7 of the Sargent patent (the asserted claims). BT contended that Prodigy was secondarily liable for infringement because subscribers who accessed the internet through Prodigy’s service were direct infringers. The district court issued a Markman order construing the terms “central computer” and “plural blocks of information,” as used in claim 3. The Markman order defined “central computer” as “a single device, in one location” that “serves as a hub of a digital information storage, retrieval and display system—and all of the remote terminals connect to it.” The Markman order construed the “blocks of information” term by observing that the first and second portions of each block were stored and located together—thus requiring that information for display be located next to information not for display. Prodigy then moved for a summary judgment of noninfringement on the grounds that: (1) the internet had no “central computer” and (2) the code for HyperText Markup Language (HTML), the primary language of the internet and of Prodigy’s internet service, did not satisfy the “blocks of information” term, as construed in the Markman order. Regarding (1), BT acknowledged that there was no centralized data store for the internet that contained all of the data that one would seek to access. BT nevertheless argued that the internet had a central computer because each Web server had its own centralized data store, namely, a main storage device for HTML files. The court also considered whether the “central computer” element could be met through the doctrine of equivalents. Regarding (2), the district court observed that HTML code did not separate information into contiguous for-display information units and not-for-display information units but instead intermingled the information to be displayed with other information related to displaying.