It's a reflection of all the systems that have their claws into the NSA database for things like FISA…
How do I know, because I have several of those letters and big shocker, they started w/the Obama administration & now line up w/known events.
They blamed China/unknown actors… It was likely all an inside job, just not sure what all they were looking for.
If it makes you feel better, they eventually got all of the DoD members security clearance background check info & digital medical records to include mental health.
The "intranet" btw is BS, I've been out for almost 4 years and my personal computer tried to access their servers couples days ago because they use SharePoint and have Google Search function active. It's a ll a big lie and more open than anyone will ever admit, in some instances we are naked to the world, IMHO…