I’ve had a further thought on why Obama did not pursue criminal charges against the bankers. As a lawyer he knew that from the beginning of the criminal law, judges developed protections for the indigent accused against the powers of the state. Bankers should not get those protections, but they do. So they can hire the highest price Wall Street law firms to take advantage of all the technicalities. Getting a banker convicted would be an uphill battle.
However, for that very reason there is a parallel civil system by which the AG can seek a fine but not imprisonment therefore none of the criminal technical protections apply.
This is the system that the AG used in suing the banks for fraud in 2016. However, suing the banks is no deterrent. They simply pass that on to us the customers in higher fees. Notice that despite all the huge fines, banker pay and bonuses remain unaffected.
The solution is to use the civil process and sue the bankers personally to the extent of all their visible property. We won’t get it all because they have undetectable large offshore holdings; but a billion-dollar fine would hurt. A greedy person hates to lose money.