Re: Something else is happening here
No IT person regardless of how bitter they are would go this far upon dismissal.
Sometimes people do strange things, for strange reasons.
Sometimes it's apparently just greed.
Every field has its share of people who are disturbed, distraught, or jut plain jerls, including IT. In this instance, if it wasn't the leaving sysadmins, it was someone else with the access and the knowledge of what was valuable.
Not too long ago, some rag did a writeup on more examples of this stuff, and how to deal with it.