You'd need to go through the legal process ie: get a court to issue a subpoena to Chase to get to the other bank, then to the other bank to get the customer inf

You'd need to go through the legal process ie: get a court to issue a subpoena to Chase to get to the other bank, then to the other bank to get the customer info, then you sue the other customer. I'm not sure if it would be you or the officer. The banking system is supposed to know who everyone is, which is the point of the KYC regulations. Extracting that information out of them is work.