Speculating, but I imagine it has to do with US requirements on financial transaction reporting. Financial institutions and securities traders have certain requ

Speculating, but I imagine it has to do with US requirements on financial transaction reporting. Financial institutions and securities traders have certain requirements on which transactions and activity they report. http://en.wikipedia.org/wiki/Money_laundering#The_role_of_financial_institutions http://en.wikipedia.org/wiki/Money_laundering#The_role_of_fi... A bank must verify a customer's identity and, if necessary, monitor transactions for suspicious activity. This is often termed as "know your customer". This means knowing the identity of the customer and understanding the kinds of transactions in which the customer is likely to engage. http://en.wikipedia.org/wiki/Money_laundering#Preventive http://en.wikipedia.org/wiki/Money_laundering#Preventive These laws, contained in sections 5311 through 5332 of Title 31 of the United States Code, require financial institutions, which under the current definition include a broad array of entities, including banks, credit card companies, life insurers, money service businesses and broker-dealers in securities, to report certain transactions to the United States Treasury. Cash transactions in excess of US$10,000 must be reported on a currency transaction report (CTR), identifying the individual making the transaction as well as the source of the cash.