Same app, different data: Explaining to the court why device and cloud data don’t match
After the second episode of Legal Unpacked, a question came in that mirrors a frequent issue raised in court: A judge asks, “You obtained data from an application on the device, and from the cloud provider for data for the same account stored remotely. Can you explain to the court why the two sets of data don’t match?” The underlying assumption is that device data and cloud data should align. In reality, they are fundamentally different, and misunderstanding that distinction risks missing potential evidence.
When investigators or forensic examiners analyze a mobile device extraction, they examine the data that physically resides on the device at the time of seizure. This type of examination often includes application databases, cached media, volatile logs, session tokens, and usage artifacts—evidence of what the user saw, did, or interacted with in real time.
In contrast, when law enforcement obtains data from a cloud provider through a search warrant, the response reflects what exists on that provider’s servers, which is information tied to the user’s account rather than the device. Although both datasets relate to the same app, they are often very different in scope, format, and completeness.
When explaining this to a judge, make sure the legal process or argument highlights two critical factors regarding the data sources: location and purpose.”
Take Snapchat as an example. Suppose an examiner reviews a local extraction from a user’s phone. The examiner may find fragments of message histories, metadata about snaps sent or received, cached story thumbnails, or artifacts showing when the user opened a chat. This data is often ephemeral, overwritten quickly, and resides on the device’s local storage independent of Snapchat’s servers. By contrast, if the same user accesses the Snapchat archiving tool at accounts.snapchat.com/v2/download-my-data, they are given a choice of 13 types of data available to download, with multiple sub-categories in many of them. The download provides more robust data, containing logs of login history, device associations, basic message metadata, friend lists, location data, and other account-level information. Even then, that download still differs from what law enforcement receives in response to a Snapchat warrant return, which is curated through Snapchat’s Law Enforcement Operations Portal and may include different retention windows, identifiers, or geolocation details depending on the warrant’s scope and Snapchat’s policies.
The reason these data sets differ lies in where and how the data reside. The local device captures a snapshot of the user’s behavior, what they were actively doing or had recently accessed. The cloud return represents a structured archive of what the provider retains, often excluding transient or cached data. The user-facing “My Data” export sits somewhere in between, offering transparency to the account holder but not necessarily the complete evidentiary picture.
Think of it this way: the mobile device is the user’s desk, scattered with notes, drafts, and reminders, some saved, some half-finished, some already thrown away. The cloud is the company’s filing cabinet at headquarters, organized, policy-driven, and containing only what the company chooses to retain. The “My Data” tool is like asking the company to mail you a copy of your own file—accurate to what they’ll share with you, but not necessarily complete.
When explaining this to a judge, make sure the legal process or argument highlights two critical factors regarding the data sources: location and purpose.
The data recovered directly from a local device and data obtained from a cloud provider are two distinct, non-interchangeable evidentiary sources. The local device is the user’s active “desk.” The desk holds the live, and often ephemeral, snapshot of user activity in real time, including data that may never synchronize, such as drafted but unsent messages, unsaved content, or application logs. In contrast, the cloud provider’s repository operates as the company’s “filing cabinet.” It only holds the data that has been intentionally or automatically stored, backed up, or synchronized, and is governed by the provider’s independent retention, storage, and deletion policies, not the user’s immediate actions.
The two sources are not duplicates and cannot be treated as such. The “desk” may hold evidence that never made it into the “filing cabinet,” because it was never synced, was deleted before synchronization, or only existed in temporary form. Conversely, the “filing cabinet” can preserve historical records that the user deleted long ago from the device. To accurately reconstruct user activity, investigative steps must address both sources through appropriate lawful means. A court should understand, from the explanation we provide in our affidavit for a search warrant, that examining only one source, by design, offers an incomplete and potentially misleading picture of the user’s behavior and intent.
Understanding these distinctions is essential for examiners and prosecutors alike. Each data source tells part of the narrative: what the user did, what the system stored, and what the provider preserved. Only by correlating all three can investigators reconstruct a more complete narrative and ensure that lawful access to digital evidence translates into meaningful proof in court.
Our in-house technical prosecutor lead, Justin Fitzsimmons, demystifies the relationship between digital forensics and the legal system. Join Justin in his webinar series Legal Unpacked, as he demonstrates how digital evidence can make all the difference in your cases.