According to FinCEN, which is part of the Treasury Department, people or businesses doing at least $1,000 per person per day worth of currency exchange, or dealing, check cashing or issuing or redeeming travelers' checks or money orders, must register with the U.S. Treasury as MSBs. Money transmitters of all sizes must register as well.

This is not the first time FinCEN has looked into money laundering at credit unions. In November, the Treasury Department fined the now-closed North Dade Community Development FCU $300,000 for failing to adequately monitor, detect and report suspicious transactions by 56 money-services businesses that were members of the credit union. Those MSBs were in what FinCEN called “high-risk jurisdictions far outside its field of membership.” In that case, 90% of the credit union's annual revenue in 2013 was from those accounts, FinCEN said. The credit union had $4 million in assets and five employees but did $1.01 billion in outgoing wires for MSBs in 2013, as well as $984 million in remotely captured deposits, FinCEN said.

Also in November, FinCEN issued a statement addressing what it said were concerns that banks were indiscriminately terminating the accounts of all MSBs or refusing to open accounts for any MSBs, thereby eliminating them as a category of customers.

“Such a wholesale approach runs counter to the expectation that financial institutions can and should assess the risks of customers on a case-by-case basis,” it said. “Similarly, a blanket direction by U.S. banks to their foreign correspondents not to process fund transfers of any foreign MSBs, simply because they are MSBs, also runs counter to the risk-based approach. Refusing financial services to an entire segment of the industry can lead to an overall reduction in financial sector transparency that is critical to making the sector resistant to the efforts of illicit actors. This is particularly important with MSB remittance operations.”

“FinCEN does not support the wholesale termination of MSB accounts without regard to the risks presented or the bank's ability to manage the risk,” it also said in the statement. “As noted, MSBs present varying degrees of risk, and not all money services businesses are high-risk.”

FinCEN has not said whether it is investigating the leak to The Wall Street Journal.

“I can't comment on any specific investigation, but I can confirm that we take the security of BSA information very seriously and there are criminal penalties for unauthorized disclosure of BSA information,” a FinCEN spokesperson told CU Times. “When disclosures occur, we refer those cases to the appropriate law enforcement agencies for potential criminal investigation.”