What they should have been doing all along. But why do "structuring" violations even exist? If someone tells me the speed limit is 65MPH and I'll violate the law going over that, so I drive at 62MPH would it be fair to charge me with "almost" doing a crime? That sucks.
The Bank Secrecy Act of 1970 (or BSA, or otherwise known as the Currency and Foreign Transactions Reporting Act) requires financial institutions in the United States to assist U.S. government agencies to detect and prevent money laundering.
Specifically, the act requires financial institutions to keep records of cash purchases of negotiable instruments, and file reports of cash purchases of these negotiable instruments of more than $10,000 (daily aggregate amount), and to report suspicious activity that might signify money laundering, tax evasion, or other criminal activities.
http://en.wikipedia.org/wiki/Bank_Secrecy_Act