Wrinkl Inc v. Slack Tech LLC

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Wrinkl, Inc. (Delaware)
  • Defendant: Slack Technologies, LLC. and Salesforce, Inc. (both Delaware)
  • Plaintiff’s Counsel: Fish & Richardson P.C.
• Case Identification: 1:24-cv-00620, D. Del., 05/23/2024
• Venue Allegations: Venue is alleged to be proper in the District of Delaware because both Defendants are Delaware corporations and therefore reside in the district.
• Core Dispute: Plaintiff alleges that Defendants’ Slack messaging platform, specifically its threaded messaging functionality, infringes a patent related to subsidiary channel-based thread communications.
• Technical Context: The technology resides within the highly competitive enterprise collaboration and group messaging market, where features that organize conversations and reduce clutter are critical for user productivity.
• Key Procedural History: The complaint notes that Defendant Salesforce acquired Defendant Slack in July 2021. The asserted patent is very recent, having issued on April 30, 2024. The complaint alleges that Plaintiff was forced to cease its own messaging services after larger competitors, including Defendants, adopted its innovative concepts.

Case Timeline

Date	Event
2015-11-10	'731 Patent Priority Date
2017-01-18	Accused Slack threaded messaging feature launch date (per articles cited in complaint)
2018-01-17	Plaintiff Wrinkl's messaging platform initially released
2021-07-01	Salesforce acquires Slack
2024-04-30	'731 Patent Issue Date
2024-05-23	Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 11,973,731 - "System and Methods for Subsidiary Channel-Based Thread Communications"

• Patent Identification: U.S. Patent No. 11,973,731, “System and Methods for Subsidiary Channel-Based Thread Communications,” issued April 30, 2024 (’731 Patent).

The Invention Explained

• Problem Addressed: The patent identifies a key deficiency in prior art group chat systems: the "sequential, read-only, chronological presentation of exchanges" which causes users to "lose track of messages if they were lost in the onslaught of team messages" and created "reply-to-all clutter." (Compl. ¶¶23-24; ’971 Patent, col. 2:56-62, col. 3:61-66).
• The Patented Solution: The invention describes a user interface and system for creating a "subsidiary" communication thread that branches off from a specific message (the "anchor message") in a main group channel. A user can select a control associated with a message, which opens a new, separate "pane" or "sidebar" for a focused, threaded conversation, while retaining a visual link to the original context in the main channel. (’971 Patent, Abstract; col. 16:60-17:3). This architecture is designed to allow private or semi-private side conversations without losing the context of the broader group discussion.
• Technical Importance: This approach aims to solve the problem of "disjointed, ad hoc electronic communications" by providing a structured way to manage side-conversations, thereby bringing "clarity and productivity back to collaboration." (Compl. ¶¶19, 24).

Key Claims at a Glance

• The complaint asserts independent apparatus claim 1, and notes that method claim 15 and computer-readable media claim 25 are infringed by a similar analysis. (Compl. ¶28).
• Independent Claim 1 of the ’731 Patent recites an apparatus configured to generate a user interface and perform steps including:
  • Generating a group communication interface with a "first pane" (for channel lists), a "second pane" (for channel messages), and a "channel text-entry field".
  • Displaying a "first messaging communication" in the second pane.
  • Displaying a "first user-selectable control" associated with that message.
  • In response to a user selection of that control, displaying a "third pane" with an associated "sidebar text-entry field".
  • Critically, the claim requires the "third pane" and its text-entry field to be displayed "simultaneously" with the first and second panes and the channel text-entry field.
  • It also requires the "first messaging communication" to be displayed "simultaneously" in both the second and third panes.
  • After receiving an "additional messaging communication" in the sidebar, the apparatus displays a "first subsidiary communication thread" in the third pane, where the first message is the "anchor message".
  • Finally, it requires displaying a "second user-selectable control" in the second pane that indicates the first message is an anchor and, when selected, causes the thread to be displayed in the third pane.

III. The Accused Instrumentality

Product Identification

• The "Slack Platform," which the complaint defines as a communications platform comprising cloud-based "Slack Servers" and client-side "Slack End-User Devices" (the "Accused Product"). (Compl. ¶27).

Functionality and Market Context

• The accused functionality is Slack's threaded messaging feature. The complaint alleges that a user can hover over a message in a channel to reveal a "Start a thread" control. (Compl. ¶46, citing Mashable article). Selecting this control opens a new pane on the right side of the application, where a threaded conversation can occur. (Compl. ¶¶40-41). The complaint provides an annotated screenshot showing this three-pane layout, labeling the channel list as the "First pane," the main message view as the "Second pane," and the new thread view as the "Third pane." (Compl. p. 17, ¶41).
• The complaint alleges these features have received "critical acclaim" and are "very popular," demonstrating their value to the Accused Product. (Compl. ¶46).

IV. Analysis of Infringement Allegations

’971 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
generate a group-based communication interface on a display screen... the... interface defining: [1c] a first pane configured to display a plurality of channel identifiers... and [1d] a second pane configured to display messaging communications associated with a selected... channel...	The Slack User Interface allegedly includes a first (left) pane displaying channel identifiers (e.g., #office) and a second (center) pane displaying the messages for the selected channel. An annotated screenshot identifies these two panes. (Compl. p. 11).	¶35	col. 8:36-54
[1h] display a first user-selectable control associated with said first messaging communication;	When a user hovers over a message, the Slack interface allegedly displays controls, including a "Start a thread" icon, which the complaint identifies as the first user-selectable control. (Compl. p. 16).	¶39	col. 24:35-39
[1i] in response to a user selection of said first user-selectable control, display a third pane, said third pane displaying said first messaging communication and having an associated sidebar text-entry field that is different from said channel text-entry field...	Upon selecting the "Start a thread" control, the Slack interface allegedly displays a third pane on the right, which contains the original message and a new "Sidebar text-entry field" for replies. An annotated screenshot shows this third pane. (Compl. p. 17).	¶40	col. 17:5-12
[1j] wherein said third pane and said sidebar text entry field are displayed simultaneously with said first pane, said second pane and said channel text-entry field;	The complaint alleges, and illustrates with a screenshot, that the third pane (thread view) and its text-entry field are displayed at the same time as the first pane (channel list), second pane (main channel), and the main channel's text-entry field. (Compl. p. 17).	¶40	col. 28:1-4
[1k] and wherein said first messaging communication is displayed within said third pane and said second pane simultaneously;	The Slack interface allegedly displays the original message (the "first messaging communication") in both the main channel (second pane) and at the top of the new thread view (third pane) at the same time. An annotated screenshot highlights this simultaneous display. (Compl. p. 18).	¶41	col. 28:5-8
[1n] display, in said third pane, a first subsidiary communication thread having an anchor message... wherein said first messaging communication is the anchor message...	After a reply is entered in the sidebar text-entry field, the third pane allegedly displays the thread, which comprises the original message (identified as the anchor) and the new reply. (Compl. p. 21).	¶44	col. 28:13-21
[1o] display a second user-selectable control associated with said first messaging communication in said second pane, said second user-selectable control being associated with an indication that said first messaging communication is an anchor message... and being configured to... [1p] ... cause [the thread] to be displayed in said third pane.	The complaint alleges that after a reply is posted, a link such as "1 reply" appears below the original message in the second pane. This link is identified as the second user-selectable control, which allegedly indicates the message is an anchor and which, when clicked, opens the thread in the third pane. An annotated screenshot illustrates this control. (Compl. p. 22).	¶45	col. 28:22-34

Identified Points of Contention

• Scope Questions: The case may turn on the precise construction of "pane". While the complaint maps Slack's UI regions to the claimed three-pane structure, a court will need to determine if the dynamic, collapsible thread view in Slack meets the specific requirements of the "third pane" as described in the patent, particularly its simultaneous display with the other two panes and their respective text-entry fields.
• Technical Questions: A key technical question is whether Slack’s "reply" counter (e.g., "1 reply") performs the function of the claimed "second user-selectable control". The claim requires this control to be "associated with an indication that said first messaging communication is an anchor message." The defense may argue that a simple reply counter is not an explicit "indication" of "anchor message" status, but merely a hyperlink showing reply activity, thus creating a functional mismatch with the claim language.

V. Key Claim Terms for Construction

• The Term: "simultaneously"

• Context and Importance: This term appears multiple times in claim 1 to define the required spatial and temporal relationship between the three panes and two text-entry fields. The infringement analysis depends entirely on whether Slack’s UI, where a thread pane can be opened and closed, meets this strict "simultaneous" display requirement. Practitioners may focus on this term because its interpretation—whether it means merely "co-existing on screen at the same time" or implies a more rigid, persistent layout—could be dispositive.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The patent’s abstract describes the panes as being "configured to be rendered within a defined display window as viewable simultaneously," which could suggest that as long as they can be viewed together, the requirement is met. (’971 Patent, Abstract).
  • Evidence for a Narrower Interpretation: Claim 1, element (j) recites that the "third pane" and "sidebar text entry field" are displayed "simultaneously with said first pane, said second pane and said channel text-entry field," suggesting a specific, all-encompassing state. (’971 Patent, col. 28:1-4). The defense could argue this requires all listed components to be present and visible together in a fixed state, not just as an optional, collapsible view.

• The Term: "anchor message"

• Context and Importance: The claim requires that the "first messaging communication" becomes the "anchor message" of the new thread and that a control indicates this status. The definition of what constitutes an "anchor message" and how that status is indicated is central to infringement.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The specification suggests that the message that initiates a sidebar conversation becomes the anchor. For example, it describes designating a message sent by a participant as an "anchor message" to initiate a private conversation. (’971 Patent, col. 24:35-39). This could support the view that simply being the first message in a thread makes it the anchor.
  • Evidence for a Narrower Interpretation: Claim 1, element (o) requires a control that is "associated with an indication that said first messaging communication is an anchor message." (’971 Patent, col. 28:24-26). This language may be interpreted to require an explicit label or status indicator beyond merely being the first message in a sequence, potentially creating a point of distinction with the accused reply counter in Slack.

VI. Other Allegations

• Indirect Infringement: The complaint alleges active inducement, stating that Defendants instruct and encourage end-users to infringe by providing and promoting the Slack Platform's threaded messaging functionality. (Compl. ¶52). It also pleads contributory infringement, alleging the Accused Product contains components that are especially made for infringement and are not staple articles of commerce. (Compl. ¶54).
• Willful Infringement: The complaint alleges that Defendants had knowledge of the ’731 Patent and their infringement "as of at least the date on which this Complaint was served." (Compl. ¶53). This is a standard allegation to support a claim for post-filing willfulness and enhanced damages. No facts supporting pre-suit knowledge are alleged.

VII. Analyst’s Conclusion: Key Questions for the Case

• A core issue will be one of claim scope and construction: Can the highly specific, multi-step process recited in claim 1, particularly the requirement for the "simultaneous" display of three distinct "panes" and two separate text-entry fields, be construed to read on the dynamic, collapsible nature of Slack’s threaded messaging user interface?
• A second central question will be one of functional and evidentiary proof: Does the accused "reply" counter in the Slack interface perform the specific, dual functions required by the patent—both indicating that a message is an "anchor message" and serving as the control to display the thread—or is there a fundamental mismatch in technical operation that could support a non-infringement finding?
• An underlying issue, though not yet raised by the defense, will be patent validity. Given the 2015 priority date, the defense will almost certainly challenge the patent's novelty and non-obviousness over the prior art for threaded messaging that existed in other collaboration tools and communication platforms before that date.