My understanding of money laundering is the baddies have huge truck loads of untaxed dirty cash and they need to somehow legitimize it to get it into the bank. E.g. from Breaking Bad: drug money → car wash with phony sales → bank. Once it’s in the bank, it’s on the radar.
The linked article says that withdrawing cash is a money laundering red flag. Can someone please explain why that is? AFAIK, if the money is in the bank it must already be clean (or appear so), no?
The question if secrecy is quite interesting. Ask a banker in the US what threshold triggers reporting. You will be told that the cutoff is a secret (and I wouldn’t be surprised if the mere question in itself triggers a report). OTOH, I don’t get how it can be a secret. AFAIK, only NSA law is a secret. All other laws are theoretically publicly open.
(exceptionally, if you want to know plumbing laws in the US you must subscribe to some professional organization in order to see the laws, strangely enough).