Funny fact: As an US citizen it is INCREDIBLE HARD to open a foreign banking account. My local German bank simply rejects ALL US customers except when they want to invest a million or more. Because the paper work is HORRIBLE. I on the other hand can easily open a banking account in Finland, Spain, Great Britain or Greece. With some limitations even in Canada, Japan and Mexiko. For an US citizen: End Boss Level. Some even have fantastic service and interest rates.
US citizens have to report all foreign accounts for tax purposes, and the foreign banks are ALSO required to file statements about the US citizens' accounts. I can understand why the banks see this as a burden and resist US customers
The same is true within the EU countries. But as far as I know the US also demands "real time access without notice to the bakn or owner of the account" and that is something which simply isn't allowed within the EU. An US citizen can in theory agree to this but then only a few banks even have the technical framework to offer such an access.
Within the EU the police can also request banking data but need a signed court order and the data isn't delivered in real time and by the bank itself and the customer gets informed afterwards.