The USDC for the Middle District of Florida ruled that the Suspicious Activity Report (SAR) Privilege protected evaluative investigative reports and communications about those reports, but did not protect the underlying transactional documents on which the bank, Wells Fargo, based its suspicious activity report. 
Wiand v. Wells Fargo Bank, 2013 WL 5925545 (M.D. Fla. Oct. 25, 2013). You may access the opinion here.
The SAR Privilege
Federal law requires financial institutions to file a suspicious activity report notifying the government of suspected criminal activity. 31 U.S.C. § 5318. And federal regulations impose an evidentiary privilege that protects from compelled disclosure all suspicious activity reports, or SARs, and “any information that would reveal the existence of a SAR.” 12 CFR § 21.11(k).
The privilege does not protect the underlying facts, transactions, or documents on which a SAR is based. Courts therefore hold that the SAR privilege “does not shield from discovery reports, memoranda, or underlying transactional documents generated by a bank’s internal investigation procedures.”
Wells Fargo Arguments and Court’s Ruling
Wells Fargo argued that the SAR privilege also protected its materials prepared to detect suspicious activity regardless whether it later filed a SAR. The court evaluated this argument and divided the putatively privileged documents into three categories for consideration: (1) transaction documents related to bank accounts; (2) internal bank emails and reports; and (3) communications between Wells Fargo and another financial institution.
The court ruled that the SAR privilege did not protect the transaction documents. Importantly, however, the court distinguished between truly transactional documents, which the privilege did not cover, and “internal reports of an evaluative nature,” which the privilege did cover.
Following this distinction, the court ruled that the SAR privilege did not cover most of Wells Fargo’s internal emails and reports, only a small portion of a page that “could be considered a report of an evaluative nature intended to comply with federal reporting requirements.”
The court held that the SAR privilege protected Wells Fargo’s external communications with another financial institution because those communications “reflect material that could be considered as a report of an evaluative nature intended to comply with federal reporting requirements.”