By any bank's own rules, a bank's proprietary funds aren't mixed. If you get a sudden amount of cash from an ATM, if you walk away from your mortgage, you aren't hurting some corporate entity. You're hurting account holders who'll be hit with lower interest rates and higher fees to make up the losses (which hurts smaller account holders more), and employees are get off. Do you think that when Citi lays off thousands of workers, they target only high-level management?
Do you have a 401K or IRA with any financial stocks? Guess what, you lose out when they suffer losses. People like Stan O'Neal and John Thain don't care. Their kind gets plenty of cash in golden parachutes, and any dips in stock prices is compensated for with more shares.
So please, consider the consequences of what could be your actions, even if you weren't punished by any laws.