DCT
3:25-cv-08689
HS Treasure Contacts Ltd v. Signal Messenger LLC
Key Events
Amended Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: H.S. Treasure Contacts, Ltd. (Cyprus)
- Defendant: Signal Messenger, LLC. (Delaware)
- Plaintiff’s Counsel: DNL Zito
- Case Identification: 3:25-cv-08689, N.D. Cal., 12/29/2025
- Venue Allegations: Venue is asserted based on Defendant's headquarters being located within the Northern District of California.
- Core Dispute: Plaintiff alleges that Defendant’s Signal Messenger application infringes a patent related to methods and systems for the "viral distribution" of mobile applications using a device's contact list.
- Technical Context: The technology at issue addresses methods for encouraging user-to-user transmission of a mobile application, a key growth mechanism in the social media and messaging application markets.
- Key Procedural History: The operative pleading is a First Amended Complaint. The complaint does not mention any prior litigation, licensing history, or post-grant proceedings involving the patent-in-suit.
Case Timeline
| Date | Event |
|---|---|
| 2008-06-24 | ’341 Patent - Earliest Priority Date |
| 2014-02-18 | ’341 Patent - Issue Date |
| 2025-12-29 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,655,341 - "Methods for mobile phone applications"
- Patent Identification: U.S. Patent No. 8,655,341 ("Methods for mobile phone applications"), issued February 18, 2014. (Compl. ¶13).
The Invention Explained
- Problem Addressed: The patent describes the challenge of distributing mobile applications at a time when many users had internet-enabled phones but limited or no PC access, creating a large "invisible market." (’341 Patent, col. 2:19-22). This was compounded by software fragmentation, where different phone models required different application versions, complicating user-to-user sharing. (’341 Patent, col. 2:48-56).
- The Patented Solution: The invention discloses a system for viral distribution where an application on a first user's device reads the user's contact list and transmits it to a central server. (’341 Patent, Abstract; Fig. 2). The server then processes this list, identifies contacts who are not yet users, and sends them invitations to install the application. (’341 Patent, col. 6:52-64). A key aspect is the server's ability to provide a version of the application that is appropriate for the new user's specific mobile device. (’341 Patent, col. 6:46-56).
- Technical Importance: The described method aimed to automate and accelerate user acquisition for mobile applications by leveraging users' social networks directly from their phones, bypassing the need for PC-based downloads and addressing device compatibility issues. (’341 Patent, col. 1:5-9).
Key Claims at a Glance
- The complaint asserts infringement of claims 1-18, highlighting independent method claim 1 and independent system claim 10 as exemplary. (Compl. ¶¶11, 20-21).
- Independent Claim 1 (Method):
- installing software on networked mobile devices;
- reading a portion of a contact list stored on the devices;
- transmitting that portion of the contact list to a server;
- sending an invitation to install the software to unregistered users from that list;
- installing the software on the new users' devices upon acceptance of the invitation;
- repeating the process for new contacts; and
- providing a server with an applications database, a client's database (subdivided into registered and unregistered sub-databases), and an application distribution unit to manage the invitations.
- Independent Claim 10 (System):
- an application running on networked mobile devices;
- a database storing a contact list of the devices;
- means for sending an invitation to install the application;
- installing the application upon acceptance;
- means to repeat the process for new contacts; and
- a server with an applications database, a client's database (subdivided into registered and unregistered sub-databases), and an application distribution unit to manage the invitations.
- The complaint asserts infringement of dependent claims 2-9 and 11-18. (Compl. ¶11).
III. The Accused Instrumentality
Product Identification
- The Signal Messenger application and associated services ("the Accused Instrumentalities"). (Compl. ¶12).
Functionality and Market Context
- The complaint alleges that the Signal Messenger application contains an "invite your friends" feature. (Compl. ¶22). This feature allegedly allows an existing user to invite non-users from their mobile device's contact list to download and install the Signal application. (Compl. ¶22). The complaint further alleges that a "Signal server" is used to run and distribute the application, store a database of existing Signal members, and, upon request, identify non-registered contacts from a user's contact list to send them an invitation. (Compl. ¶29, p. 9:5-10). The screenshots provided in the complaint depict a user navigating through the Signal app's settings to access the "Invite Your Friends" feature, which then displays the user's contact list. (Compl. p. 7).
IV. Analysis of Infringement Allegations
- Claim Chart Summary: The complaint provides a walkthrough of infringement allegations against system claim 10. The following table summarizes these allegations.
U.S. Patent No. 8,655,341 Infringement Allegations
| Claim Element (from Independent Claim 10) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a. application running on said networked mobile devices, | The Signal Messenger application, once installed and running on a user's mobile device. | ¶29, p. 6 | col. 3:1-4 |
| b. a database storing a contact list of said networked mobile devices; | The Signal app accessing the contact list stored on the user's mobile device. | ¶29, p. 7 | col. 5:18-22 |
| c. means for sending invitation to install said application on some portion of those networked mobile devices listed on said contact list; | The "Invite Your Friends" feature within the Signal application's settings menu. | ¶29, p. 7 | col. 6:60-64 |
| d. installing said application upon accepting of said invitation to install said application; | An invited contact receiving a link and installing the Signal application, for example, from a mobile application store. | ¶29, p. 8 | col. 6:13-16 |
| e. means to repeat steps b-d for each contact on each of said networked mobile devices, | The Signal application allowing users to send additional invitations after some contacts have already become members. | ¶29, p. 8 | col. 7:1-5 |
| f. a server... with... a client's database being subdivided into registered clients sub database and unregistered clients sub database... | The Signal server, which allegedly identifies contacts that are registered members and those that are not, and sends invitation messages to unregistered contacts. | ¶29, p. 9 | col. 5:22-25 |
- Identified Points of Contention:
- Scope Questions: The complaint alleges the "Invite Your Friends" feature is the "means for sending invitation." (Compl. ¶29, p. 7). This raises the question of how this means-plus-function limitation will be construed. The analysis will depend on identifying the corresponding structure in the ’341 Patent's specification and determining if the accused feature is structurally equivalent.
- Technical Questions: Claim 10 recites a server with a "client's database being subdivided into registered clients sub database and unregistered clients sub database." (’341 Patent, col. 12:14-17). The complaint alleges the Signal server performs a function consistent with this structure. (Compl. ¶29, p. 9:5-10). A central technical question will be whether the Signal back-end architecture actually implements this specific database structure or uses a different method (e.g., ephemeral, on-the-fly contact hashing) to differentiate between registered and unregistered users.
V. Key Claim Terms for Construction
The Term: "means for sending invitation" (Claim 10(c))
Context and Importance: As a means-plus-function term, its scope is not its literal meaning but is instead defined by the corresponding structure disclosed in the patent's specification and its equivalents. The outcome of the infringement analysis for this element will depend entirely on this construction.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the "application distribution unit 230" as the structure that "can contact other users 50 in order to invite them to install application 100." (’341 Patent, col. 5:27-29). This is a functional, high-level description that a party might argue covers a range of server-based invitation mechanisms.
- Evidence for a Narrower Interpretation: The specification provides more specific examples of the invitation process, stating that "server 200 sends messages, with (for example) embedded links to application 100." (’341 Patent, col. 6:60-62). A party could argue this limits the structure to a server that itself formulates and transmits the message (e.g., via SMS, MMS, or WAP PUSH as listed at col. 6:1-2), as distinct from a system where the user's mobile device generates the message via native operating system functions.
The Term: "unregistered clients sub database" (Claim 10(f))
Context and Importance: This term describes a specific component of the claimed server architecture. Whether the accused Signal system contains this precise structure will be critical for determining literal infringement.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: A party might argue the term should be construed functionally to cover any server-side data store or mechanism that holds and processes a list of non-users for the purpose of sending invitations, even if it is not a persistent or formally named database.
- Evidence for a Narrower Interpretation: Figure 1 of the patent explicitly depicts a "Client's Database" (220) containing distinct "Reg." (222) and "Non-Reg." (224) components. The specification states that "unknown users are added to a non-registered clients sub database 224." (’341 Patent, col. 6:58-59). This language suggests a specific, persistent data structure for storing non-user information, rather than a transient list used only for immediate processing.
VI. Other Allegations
- Indirect Infringement: The complaint alleges contributory infringement, asserting that Defendant supplies the Signal application and system components, which are material parts of the invention, are not staple articles of commerce, and are known to be used for infringement. (Compl. ¶25). Inducement is alleged based on Defendant providing "instructions for operation," though the specific form of these instructions is not detailed. (Compl. ¶26).
- Willful Infringement: The complaint alleges that Defendant has had knowledge of the ’341 Patent "at least since the service of the original Complaint in this action" and has continued to infringe. (Compl. ¶28). This forms the basis for a post-suit willfulness allegation.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of architectural correspondence: does the Signal back-end system, which processes user contacts to identify potential new users, contain the specific "client's database being subdivided into registered clients sub database and unregistered clients sub database" as recited in the claims and depicted in the patent's figures, or does it employ a technically distinct architecture?
- A key evidentiary question will be one of locus of action: what entity—the Signal server or the user's own mobile device—is primarily responsible for the "sending [of an] invitation" as required by the claims? The answer may turn on technical details of how the "Invite Your Friends" feature is implemented and could be critical to the construction of the means-plus-function claim terms.