Facebook Inc v. Palo Alto Research Center LLC

1. Case Identification

• Case #: IPR2021-01467
• Patent #: 8,606,781
• Filed: August 31, 2021
• Petitioner(s): Facebook, Inc.
• Patent Owner(s): Palo Alto Research Center Inc.
• Challenged Claims: 1-36

2. Patent Overview

• Title: Systems and Methods for Personalized Search
• Brief Description: The ’781 patent discloses systems and methods for personalized information retrieval. The technology purports to improve upon conventional search by identifying new, unseen information relevant to a user's goals by creating and searching a "proximal neighborhood" of documents linked to the user's access history.

3. Grounds for Unpatentability

Ground 1: Obviousness over Konig, Manber, and Van Vleet - Claims 1-16 and 19-34

• Prior Art Relied Upon: Konig (Patent 6,981,040), Manber (WebGlimpse – Combining Browsing and Searching, USENIX 1997), and Van Vleet (Patent 7,565,425).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Konig, the primary reference, discloses the core personalized search techniques of the ’781 patent. Konig teaches a "Personal Search" system that initializes a user model from browser history files (e.g., bookmarks, cache), which corresponds to the claimed "retrieving a user history" and "identifying a user profile." Konig then uses a "Personal Crawler" to find linked documents of interest, which creates the claimed "proximal neighborhood." Petitioner argued the combination with Van Vleet and Manber renders the remaining limitations of independent claims 1 and 19 obvious. Specifically, Van Vleet was cited for its explicit disclosure of a feature to restrict search results to items "not previously viewed," thereby teaching the limitation that the proximal neighborhood comprises only unseen linked elements. Manber was cited for its web crawling application ("WebGlimpse") that limits traversal to a maximum link distance (e.g., two or three "hops") from a root URL, teaching the limitation that the proximal neighborhood is "within a threshold distance" of the user's history.
  • Motivation to Combine: A POSITA would combine Konig with Van Vleet to improve the relevance of search results by filtering out information the user has already seen, a direct goal of personalized search systems. A POSITA would combine Konig with Manber because limiting a web crawler's depth is a well-known and necessary technique to prevent exponential increases in the search space, manage system resources, and maintain the topical relevance of crawled documents.
  • Expectation of Success: Petitioner contended a POSITA would have a high expectation of success, as combining these elements involved applying known search and filtering techniques to analogous web-crawling systems to achieve predictable improvements in performance and relevance.

Ground 2: Obviousness over Konig, Manber, Van Vleet, and Khan - Claims 10-12 and 28-30

• Prior Art Relied Upon: Konig (Patent 6,981,040), Manber (WebGlimpse – Combining Browsing and Searching, USENIX 1997), Van Vleet (Patent 7,565,425), and Khan (Patent 6,546,393).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground targets claims reciting that a first user's history, profile, or proximal neighborhood is used by a second user. While Petitioner argued Konig's user-clustering features inherently teach this concept, this ground provides an alternative rationale by adding Khan. Khan explicitly discloses techniques for creating a web directory from bookmarks shared by multiple users. It laments that without sharing, the knowledge in a user's bookmarks is "locked away" and teaches methods for users to import and share bookmarks with others.
  • Motivation to Combine: Khan provides a clear motivation to combine its teachings with the Konig system. A POSITA would be motivated to adapt Konig's system to allow a second user to utilize the user history (e.g., bookmarks) of a first user to harness the "analysis and positive judgment" of that first user. This would improve personalization, for example, by allowing a user to search based on the curated bookmarks of an expert in a particular field, a direct benefit described in Khan.
  • Expectation of Success: Implementing this would be straightforward, as a second user could simply provide the first user's bookmark file to the Konig system to initialize the User Model, a process already disclosed in Konig.

Ground 3: Obviousness over Konig, Manber, Van Vleet, and Cradler - Claims 17-18 and 35-36

• Prior Art Relied Upon: Konig (Patent 6,981,040), Manber (WebGlimpse – Combining Browsing and Searching, USENIX 1997), Van Vleet (Patent 7,565,425), and Cradler (Hacker's Guide to Navigator, 1997).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground challenges claims requiring the user history to be "categorized" into groups like "tasks, projects, and organizations." Cradler, a user guide for the Netscape Navigator browser, explicitly teaches organizing bookmarks into different folders to keep them "neat and orderly." Cradler specifically suggests creating folders for different "tasks or projects," directly teaching the claimed categories.
  • Motivation to Combine: A POSITA would be motivated to incorporate Cradler's well-known organizational techniques into the Konig system for the simple and practical benefit of managing a large collection of bookmarks. Since Konig explicitly contemplates using browser files (like those from Netscape Navigator) as the user history, applying Cradler's method for organizing those very files is a natural and obvious improvement for better user experience and easier retrieval.
  • Expectation of Success: The implementation would be technologically trivial, as it merely involves using a known browser feature (folder-based bookmark organization) that Konig's system was already designed to interact with.

4. Arguments Regarding Discretionary Denial

• Petitioner argued against discretionary denial under §314(a) (Fintiv) by stating that the petition was filed diligently and that the co-pending district court litigation was stayed at a very early stage. No claim construction order had been issued, and no significant discovery had occurred. Petitioner also stipulated it would not pursue any instituted IPR grounds in the district court litigation.
• Petitioner further argued against denial under §325(d), noting that none of the prior art references asserted in the petition were cited or considered during the original prosecution of the ’781 patent.

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-36 of the ’781 patent as unpatentable under 35 U.S.C. §103.