But by that logic it should be ok to monitor everything anyone does because if you do not, a person might be able do to something illegally under the cover of privacy.
I don't understand your use of "monitor" here. Banks by their very nature "monitor" your financial details, what else are they going to be doing?
Swiss banks will routinely refuse to honour legal requests for information from international law enforcement, e.g from 3rd world countries investigating their own corrupt politicians.
