DCT
5:18-cv-05970
PersonalWeb Tech LLC v. Vice Media LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: PersonalWeb Technologies LLC (Texas) and Level 3 Communications LLC (Delaware)
- Defendant: Vice Media Inc (Delaware)
- Plaintiff’s Counsel: STUBBS, ALDERTON & MARKILES, LLP
- Case Identification: 5:18-cv-05970, N.D. Cal., 10/04/2018
- Venue Allegations: Venue is alleged to be proper because Defendant is incorporated in Delaware, has a regular and established place of business in the Northern District of California, has committed acts of infringement in the district, and because the action was transferred to the district by the Judicial Panel on Multidistrict Litigation.
- Core Dispute: Plaintiff alleges that Defendant’s website content delivery system infringes patents related to using content-based identifiers, such as cryptographic hashes, to manage, locate, and control access to data in distributed computer networks.
- Technical Context: The technology concerns methods for uniquely identifying digital content based on its substance rather than its name or location, a foundational concept for modern cloud storage, content delivery networks (CDNs), and distributed data management.
- Key Procedural History: The complaint notes that the action is part of a Multidistrict Litigation (MDL) for consolidated pretrial proceedings. It also states that Plaintiff PersonalWeb has previously enforced the patents-in-suit, resulting in settlements and non-exclusive licenses. The complaint alleges infringement for the time period before the last of the patents-in-suit expired.
Case Timeline
| Date | Event |
|---|---|
| 1995-04-11 | Priority Date for ’442, ’310, and ’420 Patents |
| 2005-08-09 | U.S. Patent No. 6,928,442 Issued |
| 2010-09-21 | U.S. Patent No. 7,802,310 Issued |
| 2012-01-17 | U.S. Patent No. 8,099,420 Issued |
| 2018-10-04 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 6,928,442 - "Enforcement and Policing of Licensed Content Using Content-Based Identifiers"
- Patent Identification: U.S. Patent No. 6,928,442, "Enforcement and Policing of Licensed Content Using Content-Based Identifiers," issued August 9, 2005.
The Invention Explained
- Problem Addressed: Traditional data processing systems identify files by name and location, which is inefficient in large, distributed networks. This context-dependent naming can lead to data duplication, difficulty in verifying data integrity, and challenges in locating specific content when multiple copies with different names exist. (Compl. ¶¶14-15; ’442 Patent, col. 1:49-2:12).
- The Patented Solution: The invention proposes a system of assigning a "substantially unique," content-based identifier to each data item by applying a function, such as a cryptographic hash (e.g., MD5, SHA), to the data's content. This identifier, referred to as a "True Name," is independent of the file's name or location and changes if the content is altered. This allows for reliable identification, de-duplication, and integrity verification across a network. (’442 Patent, col. 3:7-25; Compl. ¶¶16-17).
- Technical Importance: This method of content-based addressing became a foundational element for scalable distributed storage systems, enabling efficient management of massive datasets in cloud computing and content delivery networks. (Compl. ¶13).
Key Claims at a Glance
- The complaint asserts independent claim 10 and dependent claim 11. (Compl. ¶51).
- The essential elements of independent claim 10 are:
- A method in a system with files distributed across multiple computers.
- Obtaining a name for a data file based on a function of the file's contents.
- Using that name to determine if a copy of the data file is present on one of the computers.
- Determining if a present copy of the data file is an unauthorized or unlicensed copy.
U.S. Patent No. 7,802,310 - "Controlling Access to Data in a Data Processing System"
- Patent Identification: U.S. Patent No. 7,802,310, "Controlling Access to Data in a Data Processing System," issued September 21, 2010.
The Invention Explained
- Problem Addressed: The patent addresses the challenge of managing and controlling the distribution of data in a network, ensuring that users and systems access the correct and authorized versions of files. (’310 Patent, col. 1:21-2:16).
- The Patented Solution: The patent describes a method for controlling content distribution where a first computer receives a request from a second computer that includes a content-dependent name (e.g., a hash) for a data item. Based on this name, the first computer determines if the content is "unauthorized or unlicensed" and accordingly permits or denies the second computer access to it. (’310 Patent, Abstract; col. 4:1-13).
- Technical Importance: This invention provides a mechanism for implementing access control and cache coherency in distributed systems, which is critical for CDNs to efficiently serve updated and authorized content to end-users. (Compl. ¶¶13, 29).
Key Claims at a Glance
- The complaint asserts at least independent claim 20. (Compl. ¶59).
- The essential elements of independent claim 20 are:
- A computer-implemented method for controlling content distribution between computers in response to a request.
- The request includes a content-dependent name of a data item, where the name is generated by a hash or message digest function.
- Based on the content-dependent name, a device permits access if the content is not determined to be unauthorized or unlicensed.
- Otherwise, if the content is determined to be unauthorized or unlicensed, the device does not permit access.
U.S. Patent No. 8,099,420 - "Accessing Data in a Data Processing System"
- Patent Identification: U.S. Patent No. 8,099,420, "Accessing Data in a Data Processing System," issued January 17, 2012.
- Technology Synopsis: The ’420 Patent claims a system comprising hardware and software that implements the methods described in the related patents. The system determines content-dependent digital identifiers for data items and uses one or more databases of these identifiers to selectively permit the data to be made available for access across a network of computers based on whether the identifier corresponds to an entry in the database. (’420 Patent, Abstract; Compl. ¶¶67-71).
- Asserted Claims: The complaint asserts independent claim 166, as well as dependent claims 25-27, 29, 30, 32, and 34-36. (Compl. ¶66).
- Accused Features: The accused features include Defendant's system of servers (production, origin, intermediate cache) and software used to control the distribution of its website content, which allegedly applies hash functions to files to generate ETag values and uses databases of these ETags to manage access and caching. (Compl. ¶¶67, 69, 71).
III. The Accused Instrumentality
- Product Identification: The accused instrumentality is the system and method used to operate the website
vice.com, including its use of web servers, intermediate caches, and browser caches to distribute webpage content. (Compl. ¶31). - Functionality and Market Context: The complaint alleges that Defendant's system delivers webpages comprising base files and various asset files (e.g., images, scripts). (Compl. ¶36). To manage caching and reduce bandwidth, the system allegedly generates content-based "ETag" values by applying a hash function to the content of its asset files. (Compl. ¶37). When a browser or intermediate cache requests a file it already has cached, it sends a "conditional GET" request including the file's ETag in an "If-None-Match" header. (Compl. ¶40). The responding server compares the received ETag to its current ETag for the file. If they match, it sends an HTTP 304 (Not Modified) response, authorizing the use of the cached copy. (Compl. ¶45). If they do not match, it sends an HTTP 200 (OK) response with the new file and its new ETag, indicating the cached version is no longer authorized. (Compl. ¶46). The complaint states Defendant uses Amazon's S3 system to store and serve some files, and that the S3 system generates ETags on its behalf. (Compl. ¶38). No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
U.S. Patent No. 6,928,442 Infringement Allegations
| Claim Element (from Independent Claim 10) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| obtaining a name for a data file, the name being based at least in part on a given function of the data... comprises the contents of the particular file | Defendant generates or obtains ETag values for its asset files by applying a hash function to the contents of those files. (Compl. ¶53). | ¶53 | col. 13:14-19 |
| determining, using at least the name, whether a copy of the data file is present on at least one of said computers | Defendant's servers receive conditional GET requests with an ETag and determine whether a file with a matching URI and ETag is present in the cache or on the server. (Compl. ¶54). | ¶54 | col. 3:36-40 |
| determining whether a copy of the data file that is present... is an unauthorized copy or an unlicensed copy of the data file | If the ETag in the request matches the server's stored ETag, the server's response indicates the cached copy is authorized for use. If the ETags do not match, the response indicates the cached copy is unauthorized for use. (Compl. ¶55). | ¶55 | col. 1:53-56 |
- Identified Points of Contention:
- Scope Questions: A central question may be whether an industry-standard "ETag" used for HTTP cache validation constitutes the "name for a data file" as contemplated by the patent. The defense may argue that the patent's "True Name" concept implies a more comprehensive data management system than the standard use of ETags.
- Technical Questions: The analysis may turn on whether a cache coherency check (determining if a file is stale) performs the claimed step of "determining whether a copy... is an unauthorized copy or an unlicensed copy." A court may need to decide if preventing the use of an outdated file is equivalent to deeming it "unauthorized" in the manner claimed by the patent, which is titled for policing "licensed content."
U.S. Patent No. 7,802,310 Infringement Allegations
| Claim Element (from Independent Claim 20) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| controlling distribution of content from a first computer to at least one other computer, in response to a request obtained by a first device... the request including at least a content-dependent name of a particular data item... | Defendant's upstream servers (the "first computer") receive conditional GET requests containing ETags (the "content-dependent name") from downstream browsers or caches (the "second computer"). (Compl. ¶61). | ¶61 | col. 3:52-62 |
| based at least in part on said content-dependent name... the first device (A) permitting the content to be provided to or accessed by the at least one other computer if it is not determined that the content is unauthorized or unlicensed, otherwise, (B)... not permitting the content to be provided... | If the received ETag matches the server's ETag, the server sends an HTTP 304 response, permitting the downstream device to access its cached copy. If the ETags do not match, the server sends an HTTP 200 response with new content, thereby not permitting access to the old, unauthorized content. (Compl. ¶62). | ¶62 | col. 4:1-13 |
- Identified Points of Contention:
- Scope Questions: Similar to the ’442 Patent, a dispute may arise over whether the accused HTTP-based caching system constitutes the claimed method for "controlling distribution of content." The defense may characterize its system as standard web protocol implementation, not the specific access control method claimed.
- Technical Questions: A key technical question may be whether sending an HTTP 304 response equates to "permitting the content to be provided to or accessed by" the other computer, given that the content is already present on that computer. The dispute may focus on whether this constitutes an affirmative act of permission as required by the claim.
V. Key Claim Terms for Construction
The Term: "name" / "content-dependent name"
- Context and Importance: This term's construction is fundamental. The infringement case hinges on whether the standard HTTP "ETag" value falls within the scope of this term. Practitioners may focus on this term because if "ETag" is not a "content-dependent name," the core infringement theory fails.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patents define the function for generating the name as a "message digest function or a hash function" (’310 Patent, cl. 20), and the complaint alleges ETags are generated using hash functions. (Compl. ¶37).
- Evidence for a Narrower Interpretation: The specifications frequently use the specific term "True Name" to describe the identifier, suggesting it may be a term of art within the patent distinct from any generic hash value used in a pre-existing protocol. (’442 Patent, Abstract).
The Term: "unauthorized copy or an unlicensed copy"
- Context and Importance: This phrase defines the condition upon which access is controlled. The plaintiff's theory equates a stale, cached file (with a non-matching ETag) with an "unauthorized" copy. The viability of the infringement claims for both the '442 and '310 patents depends on this interpretation.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: In a technical context, a system that prevents use of a stale file is functionally treating that file as "unauthorized" for the purpose of rendering the webpage. The claims describe a technical process, which the accused system allegedly performs.
- Evidence for a Narrower Interpretation: The title of the ’442 patent, "Enforcement and Policing of Licensed Content," suggests a focus on legal or contractual authorization (licensing), not merely technical cache coherency. The defense may argue that an outdated file is "stale," not "unlicensed."
VI. Other Allegations
- Indirect Infringement: The complaint does not plead separate counts for indirect infringement. While it alleges Defendant "caused" certain actions by downstream caches and servers, the focus of the claims for relief is on Defendant's direct infringement by its "use... and/or controlling the distribution of its webpage content." (Compl. ¶¶51, 59).
- Willful Infringement: The complaint does not contain allegations of willful infringement.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope: can the patent term "content-dependent name," developed in the context of the inventors' "True Name" system, be construed to encompass the industry-standard "ETag" header used for routine HTTP cache validation? The outcome will likely determine whether the accused standard web-serving technology falls within the scope of the patent claims.
- A key legal and factual question will be one of functional characterization: does the technical act of a server responding with an HTTP 304 (Not Modified) or HTTP 200 (OK) message based on an ETag match constitute the claimed legal determination of whether a file is "unauthorized or unlicensed"? The case may turn on whether a simple cache-freshness check is legally equivalent to the patents' claimed methods for content policing and access control.