[twoodfin]

Bank records are correspondence between a person and the bank, not “persons, houses, papers, and effects” as protected by the Fourth Amendment. As such, they’re subject to subpoena.

Now, Congress could extend similar protections to bank records any time they like. Vote accordingly.

[Gagarin1917]

Correspondence between a person and a business should be considered “papers.”

[twoodfin]

That’s not how it was understood at the time of ratification. Letters and the post office were a thing then, mentioned elsewhere in the Constitution. If the framers of the 4th amendment wanted it to cover them they would have written the amendment differently.

[Gagarin1917]

But sealed letters ARE protected under the 4th Amendment. A warrant is necessary to open all sealed mail.