I have lived in Mexico and the following is an open secret. You will find an HSBC Bank in any medium-sized city in the country. Imagine an old fashioned bank that has steel lattice work from the counter, up to the ceiling, with an opening in front of each teller big enough for a shoebox to fit through. This was a problem for the cartels until they designed steel boxes that from the front were just larger than US and Mexican notes, but the boxes are several feet long, so they can be slid (slud? sludded?) into the tellers' windows. I imagine they were filled with US $100 dollar bills, but that is only conjecture. Everyone who walked into an HSBC Bank knew this and HSBC, in the town where I lived, had very few customers, but a few BIG ones, the cartels. But somehow the FBI and other US agencies appeared blind to the facts that were clear to a casual observer. The HSBC employees, wherever they are, surely noticed the few, but massive deposits.