In modern litigation, the evidence that decides a case increasingly lives on a phone: a text thread, an ephemeral chat, a location history, a synced cloud backup. That evidence is also among the most fragile a party will ever be asked to protect. Mobile data is engineered to expire, overwrite, and synchronize automatically, which means the duty to preserve it attaches long before most clients understand what is at stake. This article examines how Rule 37(e) governs the loss of electronically stored information, why mobile devices pose distinctive preservation risks, and the defensible methodology that keeps mobile evidence admissible.
The Duty to Preserve and What Spoliation Means PRESERVATION
Spoliation is the destruction, alteration, or failure to preserve evidence relevant to ongoing or reasonably anticipated litigation, whether the conduct is intentional or merely negligent. It applies to physical objects, photographs, and documents, but in practice the modern fight is almost always over electronically stored information (ESI), and mobile communications in particular.
The duty to preserve does not wait for a complaint to be filed. It attaches once litigation is reasonably anticipated. That trigger commonly arises when a party receives a demand letter, a notice of claim, a litigation hold or preservation notice, or a letter of representation, but it can also arise from internal discussions signaling that a dispute is likely, or simply from awareness that legal action could foreseeably follow an incident. Identifying that moment accurately is a legal judgment with technical consequences, and it is why we encourage counsel to involve a forensic team at intake, before a single device is touched or updated.
Rule 37(e) and the Architecture of Sanctions
Federal Rule of Civil Procedure 37(e) supplies the framework for sanctioning the loss of ESI. By its terms, the rule is available only when ESI that should have been preserved is lost because a party failed to take reasonable steps to preserve it, and the information cannot be restored or replaced through additional discovery. Those conditions matter: not every gap is spoliation, and a backup or alternative source can defeat a motion before the court reaches the question of fault.
When those conditions are met, the rule distinguishes two tiers of remedy. Where the loss merely prejudices the opposing party, a court may order measures no greater than necessary to cure the prejudice. The most severe sanctions, an adverse-inference instruction, dismissal, or default judgment, require a finding that the party acted with the intent to deprive the other side of the information. Courts assessing reasonableness look to practical factors including the party's sophistication, its control over the lost evidence, its resources, and whether any loss resulted from the routine, good-faith operation of a retention system rather than a deliberate or reckless failure.
A recurring theme in recent decisions is that some courts have declined to credit “automatic deletion was on” as a defense. Once the duty attaches, parties, including individual custodians, are expected to take affirmative steps to suspend auto-deletion. In Safelite Group, Inc. v. Lockridge, a court sanctioned an individual who failed to preserve relevant text messages and disclaimed knowledge of his own phone's 30-day auto-delete setting, holding that even individuals must manage their preservation obligations.
Why Mobile Devices Are Uniquely Fragile
The features that make smartphones convenient are the same features that destroy evidence. Counsel should understand these failure modes before they surface in a sanctions motion:
- Auto-deletion and disappearing messages. Native messaging and apps such as Slack, Google Chat, and WhatsApp can be configured to purge content on a rolling schedule. Unless that setting is affirmatively disabled, relevant text messages vanish on their own timetable.
- Ephemeral and “history off” chats. Some platforms default to not retaining message history at all. Relying on employees to self-preserve such chats has been treated as inadequate; in the In re Google Play Store Antitrust Litigation matter, reliance on individual employees to disable a “history off” feature was found insufficient and supported an adverse-inference instruction.
- Cloud synchronization. Phone content frequently mirrors to iCloud, Google, or enterprise backup, so deletions can propagate across synced copies, and access depends on credentials and provider policies.
- Operating-system updates. An OS upgrade can alter file structures and encryption, sometimes foreclosing extraction methods that were available days earlier.
- Remote wipe. Device-management tools and consumer “find my device” features can erase a handset in seconds, often after the duty has already attached.
Because these processes run silently and continuously, the window to preserve mobile evidence is short. Waiting weeks to image a custodian's phone is itself a risk decision.
Defensible Preservation, Collection, and Chain of Custody
Defensibility is not about guaranteeing that every byte survives; no methodology can promise that. It is about showing that a party took reasonable, documented, good-faith steps appropriate to the data and the stakes. The following practices form the backbone of a defensible record.
- Issue a litigation hold promptly once litigation is reasonably anticipated, written in plain language, describing the matter, relevant time period, and data types, and expressly instructing custodians to disable auto-deletion.
- Require signed acknowledgements of the hold, send periodic reminders, and give specific direction to departing employees and to those using messaging and social-media apps.
- Have counsel actively supervise preservation. Unsupervised employee self-collection has been viewed skeptically by a number of courts; attorney oversight, ideally with forensic support, is increasingly expected.
- Capture content with court-admissible tools that preserve metadata, hash values, and timestamps, rather than screenshots, which lack metadata, are easily altered, and rarely satisfy Federal Rule of Evidence 901.
- Maintain chain of custody by recording the date and time of collection, the capture method, the responsible custodian, and hash verification, and be prepared to support it with an affidavit or expert declaration.
- Map data sources early, including cloud accounts and third-party-managed servers, and understand provider contracts governing access, retention, and backups before evidence is overwritten.
- Negotiate an ESI protocol defining custodians, sources, timeframes, collection standards, and production format, with a built-in dispute-resolution path.
Two further realities deserve emphasis. First, preservation is increasingly transparent: courts have ordered production of litigation-hold notices on a preliminary showing of spoliation, and have permitted Rule 30(b)(6) depositions probing how a party actually preserved its data. A corporate party must be ready to explain its preservation, not merely assert it. Second, the integrity of a collection is most often tested by the opposing expert. When methodology or chain of custody is challenged, an independent chain-of-custody review and, where warranted, a structured critique of the opposing forensic report are the disciplined responses, focused on method, documentation, and the limits of what the data can support.
Sound mobile preservation is ultimately a question of methodology and timing. The party that identifies the trigger date, suspends destructive processes, collects defensibly, and documents every step does not merely avoid sanctions; it preserves the credibility of its evidence for the moment it matters most.
Authorities & further reading
- Fed. R. Civ. P. 37(e)
- Fed. R. Civ. P. 30(b)(6)
- Fed. R. Evid. 901
- Safelite Grp., Inc. v. Lockridge
- In re Google Play Store Antitrust Litig.
- EEOC v. Formel D
- FTC v. Amazon
- Brown v. Tellermate Holdings Ltd.
Adapted from Law & Forensics continuing-legal-education and seminar materials (2025–2026). This article is general information for attorneys and is not legal advice; it does not create an attorney-client, expert, or consulting relationship.