Wonder if our country keeps tabs of where these wires are consistently sent (particularly high dollar amounts) and whether the capability of putting the sender info together with the recipient info has been done on anything more than a case-by-case basis. If not, it's a great opportunity missed.
The Patriot Act and previous money laundering laws targeting drug dealers address the transfer of sums of money $10,000 or more.
The feds are pretty good at tracking goblin financial transactions, which is one of the reasons they have been driven undergound and into money laundering.
In short-cash business and suitcases have replaced Western Union since 9-11.
You made the right connection, however. Its just evolved.