The regulators discovered the ACH system in 2006. The OCC issued offical guidance and the FFIEC created a new section in the BSA/AML Handbook focused solely on ACH activity. Even though the overall program was much more broad that just ACH, the recent Texas Bankers Association's Compliance School Alumni Update included a session on ACH risk.
It's clearly a growing issue for all banks.
In this world you must be oh so smart or oh so pleasant. Well, for years I was smart. I recommend pleasant.