Do explain, because I don't believe you actually know how banks work. Banks will flag up dubious transactions - uncommon large ones, frequent smaller ones, a sudden stop or start in transactions, etc. They've got big fraud (and money laundering) prevention teams on there, currently using machine learning to detect suspicious activity.

I mean there's bound to be laundering going on via banks, but it's risky.

Heard about one guy that tried to get his Bitcoin winnings onto his regular account, his bank wouldn't accept it because they couldn't verify its source. Of course, he managed to open up an account at another bank who accepted it without question, and transferring it to his main account from that bank was also done without question, so it's not exactly consistent.