Final answer:
The legislation that prohibits the violation of data belonging to banks or other financial institutions in the U.S. is the Computer Fraud and Abuse Act (CFAA).
Step-by-step explanation:
The violation of data belonging to banks or other financial institutions is indeed a crime in the United States, and the legislation that prohibits such violations is the Computer Fraud and Abuse Act (CFAA).
The CFAA, enacted in 1986 and amended several times since then, is a law that makes it illegal to access a computer without authorization or to exceed authorized access on any protected computer, which can include computers used in financial transactions.
The act aims to protect computer systems by making it a federal offense to access or cause damage to protected computers, and financial institutions often fall under this protection.