That's a fair opinion, but the law conflicts with that opinion in many places: https://en.wikipedia.org/wiki/Know_your_customer#Laws_by_cou...
Source: just finished renewing my AML training
In the US, for instance:
> financial institutions covered by the final rule must take reasonable steps to: [...] (3) determine the source(s) of funds deposited into the private banking account and the purpose and expected use of the account;
https://www.fincen.gov/fact-sheet-section-312-usa-patriot-ac...
being key...
> banking institutions;
Throwaway for obvious reasons.