"The Bank Secrecy Act is likely unconstitutional. It is either (A) so broad as to criminalize everyday life, (B) so ambiguous as to make uncertain its application to millions of Americans, or (C) spared from being so broad or so ambiguous by the exercise of legislative authority delegated by Congress to the Treasury Department." --  Peter Van Valkenburgh

It’s time to have the conversation: Is the Bank Secrecy Act unconstitutional?
Beyond the speech and privacy issues, the BSA is a sweeping delegation of law making power
https://www.coincenter.org/its-time-to-have-the-conversation-is-the-bank-secrecy-act-unconstitutional/