Section 314(b) of the USA PATRIOT Act allows financial institutions to share information with each other, under a safe harbor that offers protection from liability, in order to better identify and report potential money laundering or terrorist financing activities. The intended benefits of this information sharing include:

Participating financial institutions sharing information about suspicious activity by customers that may have otherwise gone unnoticed. For example, if a customer is conducting transactions with multiple financial institutions that individually do not appear suspicious, but collectively indicate a pattern of money laundering or terrorist financing, the financial institutions can share this information and report it to the authorities.

Detecting money laundering and terrorist financing approaches and schemes across multiple financial institutions. For example, if a financial institution identifies a new typology or modus operandi of money laundering or terrorist financing, it can share this information with other financial institutions to help them prevent or detect similar activities by their customers.

Obtaining additional information on customers or transactions regarding potential money laundering or terrorist financing. For example, if a financial institution has incomplete or insufficient information on a customer or a transaction that raises suspicion, it can request more information from another financial institution that may have dealt with the same customer or transaction.

References:

Section 314(b) | FinCEN.gov

Section 314(b) Fact Sheet - FinCEN.gov