Going Viral with New Electronic Evidence Sources

Ediscovery Cat powered by EDRM graphic with cat with laser eyes looking at man and woman surrounding a phone, with likes, loves and forwards

What are the new data sources on the ediscovery block?

The way that humans live, work, and communicate has undergone a fundamental shift over the last decade, and the velocity of change shows no signs of abating. Just this morning, I answered a Slack message, checked my email, scrolled through TikTok, answered a text message and a group chat on WhatsApp, and perused all the social media sites… then got out of bed! If I were a custodian in a matter, piecing my electronic communication together only focusing on email and documents would miss a wealth of information.

As our digital ecosystem has so drastically shifted, legal practitioners have had to rapidly adapt how and where they look for key evidence. So what exactly are the new data sources driving this change?

2019 Internet minute graph with 188 million emails sent, almost a $ million spent online, 3.8 million search queries, 1 m Facebook logins

Traditional Social Media

As the digital economy has become increasingly important to enterprise, so too have social media platforms. Organizations and their individual employees rely on LinkedIn, Twitter, Facebook, and Instagram to interact directly with potential clients, raise brand awareness, and answer customer complaints. This vast digital social footprint at the organizational and individual employee level is all potentially discoverable if deemed relevant to a case. 

Just this morning, I answered a Slack message, checked my email, scrolled through TikTok, answered a text message and a group chat on WhatsApp, and perused all the social media sites… then got out of bed!

Cat Casey

Social media requires the same consideration as any electronic evidence source and must be defensibly preserved. Deleting the incriminating tweet is still spoliation, and managed throughout the discovery lifecycle. 

New Social Media

The big four of social media (Facebook, Twitter, Instagram and LinkedIn) still maintain a strong lead, but newcomers are rapidly gaining ground and visibility as potential ESI sources. TikTok, a short format video sharing social media platform, recently surpassed 1.2 billion monthly active users. And Clubhouse, invitation-only audio-chat social networking application, has skyrocketed from a $100M valuation in December 2020 to over $1B in January 2021.

Other platforms, like Reddit, are not necessarily new but are gaining visibility as potential sources of ESI. Like legacy social media, steps must be taken early in the ediscovery scoping and planning process to account for quickly preserving and authenticating data from these sources if they may be relevant to your case. 

Ephemeral Messaging

Ephemeral messaging, as the name implies, is a form of digital communication that lasts a very short time. Generally, the genre consists of applications for short-form communication on mobile devices that disappear from the recipient’s screen after the message has been viewed. This self-destruct function is deployed in several ways, including: programmatic self-destruct function, specific trigger event (e.g. opening or closing a message), or upon the expiration of a pre-defined time frame. Deletion happens concurrently on the receiver’s device, the sender’s device, and on the system servers. Any lasting records are eradicated.

Increasingly, people from all walks of life are relying on self-destructing messaging applications (also known as ephemeral messaging) to communicate without leaving a digital trail. Given the ability to encrypt or potentially destroy messages, many people play fast and loose on these applications and they can, as a result, contain a wealth of information. While not necessarily fully destroyed, material on these applications can be very challenging and costly to retrieve — so practitioners must validate relevance. 

Virtual envelopes with fire and smoke coming out of an open envelope

Web-based Video

Web-hosted video platforms like Vimeo and YouTube have billions of users and a wealth of information that spans personal lives, makeup tutorials, editorializing, and recording events as in real time. With this breadth of information, it is no surprise that a recent report found that 53% of litigators search for discoverable content on YouTube alone. 

The content of videos as well as metadata contained within the platform (like date and time of upload, account that uploaded the video, and views) are all discoverable and effort should be made to forensically preserve all of it in the event the video is relevant to your case. 

Collaboration Tools

With the rapid shift to remote workforces over the last 12 months, collaboration tools like Slack and Teams have exploded in popularity — and with this mass adoption their potential as a key source of evidence has increased as well. While these platforms can offer substantial efficiency and benefit to an enterprise, as noted by the rapid adoption across top organizations, it also poses unique challenges in terms of ediscovery.

The problem is, collaboration tools were not designed with ediscovery in mind. Data exported directly from Slack and other tools is nearly undecipherable in its raw format, a file format called JSON. Extracting all the relevant information from a multi-person stream with links, reactions, graphics, and shared files and then presenting a cohesive picture of the data is complicated. Ensure that your provider can render this data in a usable and easily reviewable format!

Text messages in a window, and parsed into data

Video Conferencing 

Along with Slack, video conferencing platforms were widely adopted to bridge the gaps caused by social distancing. The most ubiquitous tool in the work-from-home revolution is Zoom. However, other legacy tools like GoToMeeting, Teams, Skype, FaceTime, and a myriad of other app-based videoconferencing tools are seeing rapid adoption and deployment to mitigate the disconnection of a quarantined workforce. 

Ensure that whatever technology you use has the ability to effectively parse the chat portions of Zoom or Skype as well as the video and audio portions. To surface evidence effectively, practitioners need to refine the scope of their discovery to include these increasingly dominant data sources and to adopt methods to quickly identify key information and reduce the dataverse to a manageable size. The right tools and expertise is critical as corporations learn to navigate this evolving landscape.


Text (SMS) messaging remains a cornerstone of human communication for business and pleasure and increasingly is relevant in investigations and litigation. Mobile devices are hardly a new kid on the block when it comes to inclusion in ESI requests and creating discovery headaches. In fact, even my earliest cases involved BlackBerrys, Nokias, and Palm Pilots! When the smartphone hit the stage, the nuance and complexity around mobile data in the ediscovery process was substantially amplified because the devices themselves went from a discrete and somewhat self-contained data source to a huge repository of potentially relevant information.

text message as rendered in eDiscovery review app

The instantaneous and informal nature of text messaging in particular often leads to a richness of information not seen in the more formal email exchanges. To gather a complete picture of a custodian’s activity, especially of the nefarious variety, digging into this sort of data may provide significantly more insight than traditional sources. With the increasing relevance of short form and mobile data there are some key considerations in a discovery effort.

Messaging Apps

Alternative messaging applications are also gaining traction, especially with organizations that have an international workforce. Platforms like WhatsApp and the Chinese analogue WeChat have user counts in the billions and have been used as ESI sources on several matters. As with SMS, these short forms of communication can be messy to review and contain a myriad of GIFs, emojis and abbreviations that complicate review. It is important that any ediscovery provider is able to render the material in an easily reviewable format to save time and money! 


Cat Casey

Catherine “Cat” Casey, Chief Growth Officer, Reveal Cat Casey is the Chief Growth Officer of Reveal, the leading cloud-based AI-powered legal technology company, where she spearheads development and strategy for its advanced legal technology solutions. She is a frequent keynote speaker and outspoken advocate of legal professionals embracing technology to deliver better legal outcomes. Casey has over a decade and a half of experience assisting clients with complex ediscovery and forensic needs that arise from litigation, expansive regulation, and complex contractual relationships. Before joining Reveal, Casey was the Chief Innovation Officer of DISCO, and director of Global Practice Support for Gibson Dunn, based out of their New York office. She led a global team comprising experienced practitioners in the areas of electronic discovery, data privacy, and information governance. Prior to that, Casey was a leader in the Forensic Technology Practice for PwC. Prior to that Casey built out the antitrust forensic technology practice and served as the national subject matter expert on ediscovery for KPMG. Casey has an A.L.B. from Harvard University and attended Pepperdine School of Law.

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