i think i read something like this somewhere before.
2 IT admins started mining and because they were admins only they could see the data
i think they made like $12 before someone found out and they got sacked
i think it was a trainee admin
If they were overly good at their jobs they would have received a warning, good admins aren't easy to hire.
Sometimes company executives feel it necessary to "make an example" of particular poor behavior. Being good at you job will usually help, but not always.