I've lost count of the number of economic scandals over the last few decades in which the banking system has played a central part.
Whether it's price fixing PMs
http://www.reuters.com/article/deutsche-bank-lawsuit-metals-...
the Libor scandal
https://en.wikipedia.org/wiki/Libor_scandal
the obvious high-level links to money laundering
http://www.bbc.co.uk/news/business-36768140
(and many, many more) it's obvious that banking isn't exactly the sober and reputable business it tries so hard to pretend to be.
Any other industry with this level of systemic corruption would be closed down and cleaned out.