[Yo-Yo]

The only thing I can see is that some individual, or a company purchased a product (i.e. Bitcoin, or steel or corn...) with cash.

Yup, and therein lies the rub. Did you read the IRS FAQs I linked to? Here it is again: IRS FAQs Regarding Reporting Cash Payments of Over $10,000 (Form 8300)

Whoever sold the Bitcoins failed to fill out the proper IRS form, and got arrested for it.

[M Kehoe]

Thanks.

5.56mm