3 Key Challenges to Preserving Slack Data for Litigation and Investigations
Sedona Conference releases draft commentary on handling data from collaboration platforms
In today’s workplace, collaboration tools like Slack make it seamless for teams to stay connected, share files, and communicate in real time.
But all that electronic data — measured these days in gigabytes, if not terabytes — is logged, tagged, and potentially discoverable in an investigation or litigation.
For legal professionals tasked with defensibly preserving potentially relevant data, the path is fraught with complexity. Collaboration tools were not designed with traditional ediscovery in mind. In addition to the sheer quantity of data produced in Slack, the platform presents a whole host of other discovery challenges. One of the biggest is viewing Slack data in context. Unlike emails, Slack communications are unstructured and dynamic — with multiple users, storage locations, versions of shared documents, and varying levels of retention. It’s tough to preserve, collect, and produce Slack ESI by relying on traditional ediscovery methods.
To effectively preserve Slack data, legal professionals need to understand the structure of communications in various channels and workspaces, how hyperlinked documents work within the platform, and how its retention policies impact data preservation and collection.
To help organizations, lawyers, and courts address the legal issues related to modern platforms, the Sedona Conference in April 2025 published its Commentary on Discovery of Collaboration Platforms Data for public comment. It outlines a working version of practical tips for properly preserving data from modern platforms, with a special focus on Slack, Microsoft Teams, and Google Workspace. The deadline for suggestions is May 1, 2025.
Slack Challenge 1: Navigating Custodial Ambiguity
In traditional ediscovery, the custodians — those individuals who own, control, or have access to potentially relevant information — are easily identifiable. That’s because the data in formats like emails or PDFs is tied to a personal account or device. To preserve and collect that data, legal professionals need to identify who the key custodians are.
The trouble with collaboration platforms like Slack is that they’re considered a noncustodial source of ESI where ownership lines blur. Each message is stored separately in shared workspaces and private or public channels accessed by multiple users where no single person “owns” the information. As the Sedona Conference authors point out, traditional notions of a custodian my not apply to a group workspace on a collaboration platform.
"[The] information created, shared, or maintained on a collaboration platform may not necessarily relate to or be identified with a traditional custodian," they write. "This matters because the traditional conception of ESI collection has revolved around the identification and collection of custodial information."
Legal teams have to piece Slack messages together and determine where conversations begin and end. Additionally, Slack exports data in JSON format, which only includes file links, not the actual workspace files. Without automation from an ediscovery tool to collect and display Slack messages, reconstructing full conversations becomes a complex and time-consuming task.
To overcome these hurdles, legal professionals need to work with IT and custodians to identify which channels, teams, and messages might contain relevant data. This may involve reviewing project files, emails, and meeting notes to narrow in on areas of interest. Interviewing key personnel or sending a questionnaire to potential custodians as part of the legal hold process is another way to determine whether relevant data lives in a Slack channel or workspace.
Slack Challenge 2: Preserving Hyperlinked Documents
Slack users often share documents via hyperlinks rather than attaching them directly to messages. Hyperlinked documents can be stored outside of the platform, in, for example OneDrive, SharePoint, or Google Drive, or even outside the organization, making tracking and collection more involved than with traditional email and attachments.
What’s more, hyperlinks often point to documents that have been updated or otherwise changed, adding to the complexity of identifying and producing the correct version. Revisions to the file format, metadata, or content may introduce confusion about which version of the document is the most relevant to a case and raises the risk of presenting inaccurate or incomplete information.
It’s important for legal professionals to consider where hyperlinked documents might be located and whether the records retention in those document management systems are enough for proper preservation. It’s also crucial to understand how the versioning system works and use legal holds to preserve both hyperlinked documents and the Slack communication containing the link.
Everlaw helps users consolidate documents in one place, instead of having to deal with separate files for separate attachments. The Everlaw connector treats hyperlinked files as modern attachments, capturing a unique identifier for each document and its application. When collecting the referenced document via a cloud connector, Everlaw uses the identifier to link the documents, ensuring that even if they are uploaded at different times, the links remain intact and recognized.
The Sedona Conference commentary points out that not all hyperlinked content will be relevant. Litigating parties should avoid requests for all such content by tailoring them to information that’s relevant to the matter.
By understanding how information was communicated, stored, and maintained as well as the limitations to producing hyperlinked data, legal professionals will be better able to reach agreement for the discoverability and production of these data types.
Slack Challenge 3: Preventing Auto Deletion
Slack has its own retention policies that impact whether messages and files are automatically deleted. Legal professionals need to adjust these settings to comply with legal hold requirements.
For paid plans, Slack may retain all messages, files and other information for the lifetime of the workspace. However, even in higher-tier plans, users can edit message retention settings for individual channels and direct messages.
In some cases, Slack’s settings may also limit the ability to retain data once it is deleted or expires, especially in plans where data recovery options are more restricted.
Retention settings dictate how quickly legal teams need to move to preserve evidence — whether through in-place holds or urgent collection — and influence strategies to avoid spoliation. Autodeletion policies may require immediate action while indefinite retention gives teams more flexibility (although the latter risks overretention).
Legal teams should work with IT to ensure that data pertinent to a case is not automatically deleted. A custom retention policy can be set to prevent automatic purging of potentially relevant messages and files. Refer to Slack’s guidance for the latest policies.
The Sedona Conference commentary advises legal teams to always determine whether a collaboration platform can preserve data under legal holds and how it handles this process. The platform should also be capable of automatically deleting or purging data once the retention period ends or the legal hold is lifted, ensuring that data is properly managed throughout the legal process.
Understanding Slack’s Capabilities and Configurations
Since launching to the public in 2013, Slack has made everyone’s work life easier and more productive. Except for legal professionals handling ediscovery.
The messages, files, and document links shared across Slack’s variety of channels and workspaces complicates the task of isolating key communications, resolving hyperlinked documents to their correct versions, and aligning content within a relevant context. The noncustodial nature of Slack requires greater diligence in identifying potential users and collaborators who may turn out to be custodians or witnesses. And without the correct retention settings, potentially relevant data can be irretrievably lost.
Understanding these challenges and applying the appropriate discovery strategies can help legal professionals navigate Slack data preservation with greater ease and confidence.
Read more about ediscovery best practices for Slack and other collaboration platforms in the comprehensive guide, How Collaborative Tools Are Changing the Face of Ediscovery.
