So the worst case penalty for fraud is possibly having to give back what you stole? Given a non zero chance of not getting caught, that makes fraud a positive expected value course of action.
If society didn't exist, maybe. But in real, functioning societies, people care about their standing, and being seen as a fraudster is not a positive outcome. If "being seen as a fraud and outcast for life" is a possible outcome, people in normal societies don't give that risk zero value. So it doesn't always require actually imprisoning someone to deter behavior. Keeping someone locked up in a cage is a pretty extreme sanction, both expensive and odious and best reserved for really rare cases where there is no other alternative. Usually that means violent crimes with no reasonable prospect of releasing the perpetrator without recidivism, in which case imprisonment is a last resort to protect society—Breivik type cases. Beyond that, imprisoning someone is prima facie evidence of failure, a knee-jerk reaction to not being able to run a financial (or other) system properly.
This doesn't sound like it's just fraud, but full on mental delusional stuff. In that case throwing him in jail is probably not going to help matters by itself, and he needs doctors. Ideally some mix of the two.
I've known people like this, luckily that didn't get backed, and it can get incredibly messy. Things like maxing credit cards, identity changes, disappearing to foreign countries. It's better for everyone in the long run that this gets sorted properly as he'll just emerge from prison desperate to get back and will do something worse.
How does this case sound any different than, say, Bernie Madoff?
On the face of it, it sounds like a much more blatant fraud than Dennis Kozlowski, the former Tyco CEO who served about 8 years in prison, or Bernie Ebbers (what is it with guys named "Bernie"?), who is still serving a 25 year sentence for defrauding WorldCom investors.
People stealing money and behaving erratically when it collapses around them isn't evidence of mental illness. Maybe he's nuttier than a squirrel hole, but right now, I don't see any reason to assume he's not just a criminal.
Got to say, your Madoff comparison is annoyingly good.
One main difference is Madoff wasn't alone. He needed the help of a group in on the conspiracy over a long period of time. Combined with the overall magnitude and the regulatory failures I'm much more persuaded Madoff had criminal intent. This case sounds a lot like he was lying to absolutely everyone all the time (and especially to those closest to him), not that he was trying to orchestrate some group conspiracy to fleece outsiders of their cash. The whole story isn't out yet, so maybe there is more, but it sounds to me like he's one of those people that genuinely believes that if you act rich you become it.
Forgive me - I wasn't speaking in general terms about what I believe should happen to any individual who commits fraud, which I think your reply presupposes.