>>511459776You're correct. Though the juicy part comes from aggregating multiple datasets of unclassified information that, when compiled, may potentially upgrade to classified information.
https://csrc.nist.gov/glossary/term/data_aggregation
However, the individual files themselves are never classified. I can guarantee this. All information stored on federal systems are marked by the type of data classification. You don't see classified documents on unclassified systems. Not to say leaks are impossible though, because there has been cases in which cleared personnel leaked secret & top secret documents. But that's entirely different from having them stored on cloud infrastructure such as Sharepoint servers. We have detection/prevention technologies for this and it triggers alerts to security personnel.