Dwelling House Savings & Loan Association, one of the country's few institutions to provide bank accounts to prisoners, failed last year after regulators warned the Pittsburgh S&L that its computer systems were vulnerable. Dwelling House was later hacked by cyber-thieves, who siphoned as much as $4 million out of its coffers.
Most criminals are truly stupid--unintelligent, uneducated--because criminality tends to not payoff in the long run, and stupid people overweight the short-run payoff. One might therefore conclude that computer theft would not be a concern, but this highlights that bad faith is very important because if there's a will, there's a way. Knowing your customer, or adversary, is very important because their end game often predicts tactical behavior.