Whoa there, bubba. The military and CIA have no constitutional right to look through the records of American citizens. If they suspect terrorism, they can use the FISA court to get a warrant.
Don't toss the Fourth Amendment out the window in the name of security. I can't really imagine a situation where bank records are so urgently needed that they can't take an hour or so to make a case to the FISA court.
I highly suggest following the link and reading the article in full before commenting.
Government lawyers say the legal authority for the Pentagon and the CIA to use national security letters in gathering domestic records dates back nearly three decades and, by their reading, was strengthened by the antiterrorism law known as the USA Patriot Act.
Not only that, but anyone operating within the US banking system at least at those facilities insured by the FDIC and FSLIC the government has access to data on individual banking customers whenever it wants to access it. Any institution insured by the federal government has to give federal regulators access to their records during any extensive examination. Not only that, but since most accounts pay interest, the IRS also gets all of the information on these accounts, including taxpayer numbers and other private information.
Within the Patriot Act, which both parties passed, the use of National Security Letters, for investigating these such things is provided for. Please just read the entire linked article. Reading only the excerpts here could be misleading to the entire issue addressed.