Key insight: St. Louis fraudster combined a decades' old scam with modern technology to abscond with $6 million from banks.What's at stake: Bank fraud works because the fraudsters move faster than banks can track them; modern tools turbocharge that advantage.Forward Look: Regulators are weighing changes to check-processing policies to better address fraud.Last Tuesday, a federal judge sentenced a St. Louis man to six years in prison for orchestrating a check-fraud ring that stood to defraud banks and custom ...