> You don't want to allow [...]

Yes I do. A Judge decided what was a fair punishment for the offense. They sat through an entire trial and made a decision about what was an appropriate sentencing.

Once that appropriate sentence has been serve there should be no further punishment. If the Judge decides the felon should never be able to work in banking they can, in most countries, make that happen.

What's the point of having a judicial system if everyone is going to take the matter in their own hands anyway?