The Feds asked for the information - I imagine they were all asked.
The Fourth Amendment to the Constitution would seem to apply here:
“The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no warrants shall issue, but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.”
If the government “asked BOA”, but produced no warrant, BOA was under no obligation to violate the privacy of its customers and security of the papers and personal information of its customers. Unfortunately the cost for an individual to sue BOA and the federal government would be astronomical. In today’s world finding a competent lawyer would be hard enough. Then the government and BOA will drag out discovery for years. Getting an unbiased judge is another obstacle. Finally any citizen who isn’t independently wealthy will see his job lost, harassment by the IRS, and other pressures.
Assume he finds the money, and is willing to go through living hell for the next ten years. He appeals to the Supreme Court, likely increased in size and dominated by leftists. They simply refuse to hear the case, or even worse “interpret” the words to state “voluntary” compliance to such warrant less requests by government are ok.
The average citizen cannot afford the legal process today, much less expect the judiciary to protect his constitutional rights. Hence freedom is dead.