Congress has subpoenaed Citibank for giving up customer financial data to the FBI so they could go after January 6th protestors
The FBI was interested in customers transacting in Washington D.C. and any customers who had made “ANY historical purchase” of a firearm. They didn't go through any legal process to request the information yet the bank just let them have it.
Citibank previously got an information request letter and they didn't comply, which forced the judiciary committee to send this congressional subpoena.