[m0ngr31]

Sure, but presumably they weren't working as a security engineer at the time.

Or think of it this way...

Could someone not be a doctor if they had assaulted someone before medical school?

Would a lawyer not be able to be admitted to the bar if they had been convicted previously?

I'm actually not sure about those, they both might not be allowed. I just lean on the side of forgiveness once you've "paid your debt to society".