The hunt for the criminals is a waste of time. People were acting aggressive, not criminal--with notable exceptions that could happen in any era. In fact, finding scapegoats will make the problem worse. It leaves the system intact and fools everybody into believing the problem is fixed.
Credit and risk has always been a problem of information. In this era we have more tools than ever to manage them. However the rules require a major rethink to get the right information circulating.
Now, if you believe it is a systems problem, what's the solution? Here's one: Transparency. Not the SEC's version of quarterly accounting quibbles. Just tell me the the end-of-day positions of every "large" participant. 20 years ago that would be too much information to process. Now it would be no problem. Lots of little agencies could process the information.
The impact would be enormous. The informational advantages of large institutions and so-called speculators would simply disappear. Nobody would be able to grow to be too big to fail, simply because they would have a harder time trading. If you are starting to feel sorry for banks having to supply this type of formerly proprietary information, just remember, they have the corresponding information on you and you don't complain.