Managers to blame
"Excellus said it was working with the FBI"
Whoops, those idiots can only work with "Future Crimes" they happen to find in Internet chat rooms, like the swiftly averted Massive Polar Bear Attack of 2012!
This is another example of managers saving a buck, at the expense of some helpless customers later on! (Wow! That's just super super sad) Let's do bugger-all about security then we we get hacked and notice it two full years later we can offer the victims some cheap identity checking service and go on about our business of doing the same thing again. And again. And again. 100% it's dopey managers. Most admins I know are security sensible, most managers are into cutting corners and doing it FAST, not well.
Trying to figure out a crime that already happened isn't in the FBI wheelhouse. They are super good with investigating song lyrics though. Top guys when crimes might be hiding in song lyrics!