The holy Grail of documents is the DD-214, which has every single piece of sensitive personal information a civilian has, all in one place, and we are REQUIRED to keep it indefinitely, to present it under a large number of circumstances. It's a complete identity package; full name, signature, photo, work history, residence history, dates, personal description, mother's maiden name, date of birth, location of birth, name of birth hospital and doctor. Then there's security clearance paperwork, which may be even worse, extensive un-redacted medical records, etc.
All of these documents are viewed hundreds of times by hundreds of people during a military career, scanned, photocopied, emailed, printed, all without any sort of authorization or even knowledge by the service member. It's legitimately scary. And then after you're out, all of this information is managed by the VA by people who have nearly unrestricted access to it, and in my case along with thousands of others, put on a thumb drive and taken home and sold to a broker. It's a life ruiner.
- https://en.wikipedia.org/wiki/Standard_Form_86
The OPM data breach (2015) affected service members, civilian government employees, and other civilians
- https://en.wikipedia.org/wiki/Office_of_Personnel_Management...
Hostile foreign powers are a problem, but so are hostile domestic extremists along with a large population of the mentally ill who over the last century have gone from being abused to being ignored, which means that while most of the mentally ill are harmless, nobody is keeping an eye on the ones who aren't. Not even after they get repeatedly reported to authorities by concerned family members (Robert Card, Ethan Crumbley, Orlando Harris, etc).