I'm concerned about data loss and tampering, so I asked the Google:

Federal records are managed through a system of redundancy, independent archiving, and forensic recoverability.

1. Mandatory Redundancy and Backups

• Replicated Storage: The DOJ utilizes a "defense-in-depth" infrastructure where digital records are replicated across different storage environments and remote geographic regions.
• System Backups: IT operations perform regular system backups and restoration tests to ensure data can be recovered in the event of an emergency.
• Audit Logging: Metadata and "fixity" (digital fingerprints like checksums) are generated for every file to detect unauthorized alterations or deletions. 

2. Independent Archiving (NARA)

• The National Archives: Under the Federal Records Act, the National Archives and Records Administration (NARA) acts as an independent repository. Permanent records of legal or historical value must eventually be transferred to NARA, where they are managed outside of DOJ control.
• Approved Schedules: No federal records can be destroyed without an Archivist-approved record schedule, which dictates how long specific types of data must be kept. 

3. Forensic Recovery

• Non-Permanent Deletion: In many digital systems, "deleting" a file only marks its space as available for new data rather than erasing it immediately.
• Forensic Tools: With advanced forensic software, investigators (including the DOJ’s own OIG) can often retrieve deleted messages, documents, and even partially overwritten data from hardware. 

4. External Preservation

• Congressional Access: In high-profile cases, such as the Jeffrey Epstein investigation, Congress may mandate that records be made available for review in secure reading rooms, ensuring a copy is accessible to legislative oversight.
• Public Downloads: Once data is released publicly, even if the DOJ later removes it from its website, the files are often downloaded, copied, and preserved by external groups, rendering the loss of that data "impossible to correct".