Well there's also a c) - Whatever they get away with now they will have in pocket, and whatever penance they will have to do with a future administration will take years and years of legal back and forth to actually pan out, by which time it will be watered down so any fine will dwarf the profits made during this period.

Also, if they manage to reach "too big to fail" status by that point, whatever punishment will be nothing more than a slap on the wrist.