Challenges Of Cross-Border Data Protection Laws
Recent Cases Spotlight the Challenges of Cross-Border Data Protection Laws in eDiscovery
June 20, 2019

New Cases Spotlight Production Pitfalls in eDiscovery with Slack

Production Pitfalls in eDiscovery with Slack

Slack is a popular cloud-based team collaboration and messaging platform used by a wide variety of organizations. Similar to other messaging platforms that have grown in popularity, Slack is unknown to many counsel and courts. Nevertheless, content from Slack is increasingly being sought by parties in discovery. A lack of knowledge about Slack or similar technology can lead to complications with preservation, collection, and production. This is apparent from two recent court cases that addressed failures to produce relevant messages from Slack.

What is Slack?

Cloud-based messaging and collaboration platforms like Slack have gained increasing prominence over the past several years. Also referred to as workplace collaboration tools, these technologies—like social networking applications—provide employees with a highly interactive and customizable platform to communicate with co-workers and share documents. Many users believe these platforms provide a significant improvement over email or other messaging applications, which they perceived as less flexible and too “corporate.”

First released in 2013, Slack has proven to be an especially popular messaging and collaboration tool. Billed as a secure communication app that can help “everyone save time and collaborate together,” Slack touts its multifaceted functionality of discussion “channels” for larger groups, “direct messages” for one-on-one exchanges, and “private channels” to communicate sensitive information. With an advanced application processing interface (API) and the ability to automate functionality and workflows, users have flocked to Slack, vaulting the company from start-up status to financial juggernaut listed on the New York Stock Exchange with a valuation of approximately $17 billion.

Discovery of Slack Messages

Slack has several eDiscovery partners (including Relativity) that have developed applications to efficiently obtain data from Slack for processing, review, and production. As detailed on Slack’s website, app creators can use Slack’s eDiscovery APIs to “pull messages and files from Slack, and store the information in third-party data warehouses.” From there, message content including files can be “searched, archived, or retrieved.”

This was not always the case. Before Slack developed specific APIs for eDiscovery, the process for obtaining Slack data was less transparent and more akin to a “black box.” This led to technical and workflow challenges in the discovery process, resulting in production delays and high costs.

While Slack has generally addressed those issues through its discovery APIs, litigants could still experience production problems if they, their counsel, or their eDiscovery service providers are unaware of or bypass the eDiscovery data extraction methods that Slack has established. Parties could also be tripped up if they use free Slack accounts instead of premium (paid) accounts, as Slack will not allow users to extract messages from free accounts. Some combination of these problems created production delays and led to the corresponding orders in Calendar Research LLC v. StubHub, Inc.[1] and Milbeck v. Truecar, Inc.[2]

Calendar Research v. StubHub

In Calendar Research, plaintiff filed a discovery motion seeking production of Slack messages from two of the individual defendants. Plaintiff did so after finding that defendants had produced “Slack email notifications, which alert users to pending messages, but not the messages themselves.” In response to plaintiff’s motion, defendants began producing the requested messages.

According to the court, this did not entirely moot the motion to compel since defendants had yet to complete their production of Slack messages. U.S. Magistrate Judge Suzanne Segal observed that defendants were tardy in accomplishing the production due to technical problems they experienced trying to export messages from Slack.

The technical problems arose because defendants had communicated on Slack using a free corporate account, thus postponing production of their relevant messages until they upgraded to a “premium account.” Production was further delayed because Slack would not give defendants a complete export from the corporate account given that it included data from other users who were not parties to the litigation and whose consent to the export had not been obtained. While refusing to provide a complete export, Slack did supply defendants with a “utility tool” that enabled them to obtain the messages from their “private channels.” In the midst of navigating these technical issues during the pending motion, Judge Segal issued a production order to ensure defendants followed through and completed their production of relevant Slack messages.

Milbeck v. Truecar

In contrast to Calendar Research, the court in Milbeck denied plaintiff’s motion to compel production of relevant Slack messages from defendant TrueCar. Like Calendar Research, there was no dispute over the relevance of the Slack messages. Instead, the Milbeck holding focused on the apparent disproportionality of producing the requested information, i.e., the burden of producing the Slack messages outweighed any benefit the information could provide to plaintiff in discovery. According to the court, this was because defendant’s production of the requested Slack messages would apparently not be finished until after discovery cutoff had passed.

The court’s finding of disproportionality was premised on a declaration from a project manager working for TrueCar’s eDiscovery vendor. In that declaration, the project manager stated that TrueCar received 1.67 gigabytes of compressed data from Slack. However, the declaration omitted several key facts including the following:

  • The process for extracting the data from Slack.
  • What attempts (if any) were made to filter the Slack data prior to collection.
  • Whether the extracted Slack content contained only text or a combination of text, images, and attachments.

Detailed responses to these questions and others would likely have altered both materially and fundamentally the factual conclusions in the declaration.

The project manager also made questionable assertions about the potential volume of Slack messages that would be extracted for review (allegedly up to 17 million messages) as well as the technical complexities and time required for processing and reviewing Slack data. One particularly dubious statement from the declaration was the project manager’s conclusion that “there is no way to isolate any specific information, such as particular channels or users and limit the collection to only that data.” This statement runs contrary to the factual findings in Calendar Research that Slack has a “utility tool” (i.e., an API) that enables parties to extract specific users or certain user channels. Nor does that assertion accord with the established process Slack has delineated on its website regarding this issue.[3]

Without the benefit of a counter-declaration from plaintiff, the court adopted the conclusions from the declaration at issue and found that a production of Slack data after the discovery cutoff would be of no value to plaintiff. As a result, the court denied plaintiff’s motion to compel.

Addressing Slack in eDiscovery

Given the increasing use of Slack among clients and considering the issues mentioned in Calendar Research and Milbeck, lawyers should develop protocols so they are better prepared to address discovery issues relating to Slack.

As we have emphasized with other electronic communication technologies, counsel should add Slack to its checklist of possible sources of relevant information and to its custodian interview questionnaire. Doing so will better ensure that Slack is not overlooked when considering sources of relevant information.

If the client is using Slack, counsel should develop an understanding of how the technology has been implemented and the steps for preserving and then collecting such information for review and production. This should be done right away since the manner in which the technology has been licensed may—like in Calendar Research—impact the client’s ability to obtain and then efficiently process Slack content for search and review.

A final consideration is ensuring that eDiscovery service providers have competent personnel, along with effective tools and procedures, for processing and reviewing Slack data. Providers with experienced and technically savvy experts and staff who follow best practices for processing Slack messages can likely avoid the processing difficulties and resulting delays that were alleged to be so problematic in Milbeck. They can also offer testimony to substantiate arguments on the issues or refute questionable conclusions like those from TrueCar’s declaration in Milbeck.


[1] Calendar Research LLC v. StubHub, Inc., No. 17-cv-4062, 2019 WL 1581406 (C.D. Cal. Mar. 14, 2019).

[2] Milbeck v. Truecar, Inc., 18-cv-02612, ECF 137 (C.D. Cal. May 2, 2019).

[3] See e.g., Slack App Directory: Relativity, available at: https://slack.com/apps/A3WTX78L8-relativity (last viewed July 3, 2019) (“Once installed, administrators can select Slack data from specific users or channels for import, schedule a reoccurring job to import new data, and map specific Relativity fields to Slack metadata for targeted analysis.”).

Philip Favro
Philip Favro
Philip Favro acts as a trusted advisor to organizations and law firms on issues surrounding discovery and information governance. Phil provides guidance on data preservation practices, litigation holds, data collection strategies, and ESI search methodologies. In addition, he offers direction to organizations on records retention policies and the need to manage dynamic sources of information found on smartphones, cloud applications, and social networks. Phil is available to serve as a special master on issues related to electronic discovery. Phil is a nationally recognized thought leader and legal scholar on issues relating to the discovery process. His articles have been published in leading industry publications and academic journals and he is frequently in demand as a speaker for eDiscovery education programs. Phil is a member of the Utah and California bars. He actively contributes to Working Group 1 of The Sedona Conference where he leads drafting teams and serves as the Steering Committee project manager. Prior to joining Driven, Phil practiced law in Northern California where he advised a variety of clients regarding business disputes and complex discovery issues. He also served as a Judge Pro Tempore for the Santa Clara County Superior Court based in Santa Clara, California.
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