Big banks are getting away with far too much. There seems to be this idea that they are too big to fail because their failure would crush our infrastructure and economy.
One example is the recent HSBC case. They laundered millions for Mexican drug cartels, and routed thousands of transactions linked with nations under sanctions, in some cases due to links to terrorism. The $1.9 billion fine is said to be equivalent to about 4 weeks worth of their profits, and none of their executives are seeing any jail time.
The current penalties applied to big banks is not enough to truly deter this kind of criminal activity. Harsher penalties need to be applied before things get worse.