As long as we prosecute as many people in their position as possible it doesn't seem to be a problem if we miss some. It's only selective when we choose who to ignore.
Something like Aaron Schwartz where it wasn't a crime until someone who made the DA look like an idiot does it... Then it's clearly crossed the line.
Or even just the possibility of piercing the veil of incorporation, ie let the employees take some risk on the downside, too.
If a bankster's danger to society can be remedied by banning him from his chosen profession, and justice served with a fine, it does seem like we could spare the cage.
And maybe we could spare the cage... But after we get around to the mistakenly (cough) convicted black people, and poor people, and those with mental illness, etc, then we can worry about the poor-banker in his comfortable minimum-security cell.