That's if you're laundering money deliberately. There are many things which are legally classified as "money laundering" even when no actual (other) criminal activity is involved. It's a "prove your innocence" situation—if you don't file the required paperwork and prove to the government's satisfaction that no laundering is taking place they will call that "money laundering" on its own. Or even if you do file all the paperwork officially required but your transactions resemble "structuring", whether deliberately or accidentally.

The 4th Amendment should have been read as including all financial transactions among "papers, and effects". AML/KYC laws are completely incompatible with a free society.