The complaints began as soon as federal agents raided the Baltimore law firm’s offices in June 2019. With investigators rifling through documents and searching computers, attorneys with Brown, Goldstein & Levy urged them to only seize materials directly connected to the lawyer and client named in the money-laundering probe.

No one did so. But a year later, a trio of justices with the U.S. Court of Appeals for the Fourth Circuit sided with the firm in an opinion that likened the U.S. Department of Justice’s process for filtering potentially attorney-client-privileged material to “the government’s fox in charge of guarding the law firm’s henhouse.”