[Editor’s Note: John C. Ellis, Jr. is a National Coordinating Discovery Attorney for the Administrative Office of the U.S. Courts, Defender Services Office. In this capacity, he provides litigation support and e-discovery assistance on complex criminal cases to defense teams around the country. Before entering private practice, Mr. Ellis spent 13 years as a trial attorney and supervisory attorney with Federal Defenders of San Diego, Inc. He also serves as a digital forensic consultant and expert.]
Ephemeral Messaging Apps are a popular form of communication. With privacy a concern for everyone, using a self-destructing message that works like disappearing ink for text and photos has a certain allure. All messages are purposely short-lived, with the message deleting on the receiver’s device, the sender’s device, and on the system’s servers seconds or minutes after the message is read. Although these apps were initially only used by teenagers, they are now a ubiquitous part of corporate culture.
According to the 6th Annual Federal Judges Survey, put together by Exterro, Georgetown Law CLE, and EDRM, 20 Federal Judges were asked “[w]hat new data type should legal teams be most worried about in the 5 years?” The overwhelming response was “Ephemeral Apps (Snapchat, Instagram, etc.).” Id. In fact, 68% of those surveyed believed ephemeral messaging apps where the most worrisome new data type, whereas only 16% responded that biometric data (including facial recognition and fingerprinting) were the greatest risk. Only 5% were concerned with Text Messages and Mobile, and 0% were concerned with the traditional social media such as Facebook and Twitter. Id.
Even now, Courts are attempting to sort out the evidentiary issues cause by ephemeral messaging apps, see e.g., Waymo LLC v. Uber Technologies, Inc. 17cv0939-WHA (NDCA). This article discusses popular ephemeral messaging apps and discusses guidelines for addressing potential evidentiary issues.
Short technical background:
There are several background definitions relevant to this discussion:
- Text Messages – otherwise known as SMS (“Short Message Service”) messages, text messages allow mobile device users to send and receive messages of up to 160 characters. These messages are sent using the mobile phone carriers’ network. Twenty-three billion text messages are sent worldwide each day. Generally, mobile carriers do not retain the contents of SMS messages, so the records will only show the phone number that sent or received the messages and the time it was sent or received.
- Messaging Apps – allow users to send messages not tethered to a mobile device (e., a phone number). With some apps, a user may send messages from multiple devices. These apps include iMessage, WhatsApp, and Facebook Messenger. Messaging Apps are generally free. Unlike text messages, these apps rarely have monthly billing records or records showing when messages were sent or received.
- Ephemeral Messaging Apps – are a subset of Messaging Apps that allow users to cause messages (words or media) to disappear on the recipient’s device after a short duration. The duration of the message’s existence is set by the sender. Messages can last for seconds or days, unless the receiver of the message takes a “screenshot” of the message before its disappearance.
- End-to-End Encryption – also known as E2EE, this is a type of encryption where only the communicating parties can decipher the messages, which prevents eavesdroppers from reading them in transit.
Common Disappearing Messaging Apps:
Messaging apps, like all apps, are changing. The following is a list and description of several popular ephemeral messaging apps.
|Snapchat – both a messaging platform and a social network. The app allows users to send messages and media (including words and emojis appearing on the media) that disappear after a set period of time. Photos and videos created on Snapchat are called “snaps.” Approximately 1 million snaps are sent per day.|
|Signal – an encrypted communications app that uses the Internet to send one-to-one and group messages which can include files, voice notes, images and videos, which can be set to disappear after a set period of time. According to Wired, Signal is the one messaging app everyone should be using.|
|Wickr Me – a messaging app that allows users to exchange end-to-end encrypted and content-expiring messages, including photos, videos, and file attachments.|
|Telegram – cloud-based instant messaging app with end-to-end encryption that allows users to send messages, photos, videos, audio messages and files. It has a feature where messages and attachments can disappear after a set period of time.|
|CoverMe – a private messaging app that allows users to exchange messages, files, photographs, and phone calls from a fake (or “burner”) phone number. It also allows for private internet browsing, and allows users to hide messages and files.|
|Confide – a messaging app that allows users to send end-to-end encrypted messages. The user can also send self-destructing messages purportedly screenshot-proof.|
Messaging app data, like other forms of evidence, must, amongst other criteria, be relevant (Fed.R.Evid. 401); authenticated (Fed.R.Evid. 901 et seq); and comply with the best evidence rule (Fed.R.Evid 1001 et seq).
As for the Best Evidence Rule, based on the nature of disappearing messaging apps, the original writing of the message is not preserved for litigation. See Fed.R.Evid. 1004(a) (finding that the original is not required if “all the originals are lost or destroyed, and not by the proponent acting in bad faith.”) Sometimes, the contents of the message may be established by the testimony of a witness. In other cases, the contents of the message may be based on a screen shot of the message.
Authenticating messages from apps, regardless of their ephemeral nature, is often difficult—text messages can be easily faked. When it comes ephemeral messages, we often must rely upon a screenshot or testimony regarding the alleged contents of the message. In such circumstances, the following factors—repurposed from Best Practices for Authenticating Digital Evidence—are useful:
- testimony from a witness who identifies the account as that of the alleged author, on the basis that the witness on other occasions communicated with the account holder;
- testimony from a participant in the conversation based on firsthand knowledge that the screen shot fairly and accurately captures the conversation;
- evidence that the purported author used the same messaging app and associated screen name on other occasions;
- evidence that the purported author acted in accordance with the message (e.g., when a meeting with that person was arranged in a message, he or she attended);
- evidence that the purported author identified himself or herself as the individual sending the message;
- use in the conversation of the customary nickname, avatar, or emoticon associated with the purported author;
- disclosure in the message of particularized information either unique to the purported author or known only to a small group of individuals including the purported author;
- evidence that the purported author had in his or her possession information given to the person using messaging app;
- evidence that the messaging app was downloaded on the purported author’s digital device; and evidence that the purported author elsewhere discussed the same subject.
Ephemeral messaging app data will continue to impact investigators, attorneys, and the Court. Defense teams should be prepared for the challenges ephemeral messages cause from investigations to evidentiary issues.
 Hon. Grimm, Capra, and Joseph, Best Practices for Authenticating Digital Evidence (West Academic Publishing 2016), pp. 11-12.