I’ve gradually accumulated about a dozen one-ounce silver rounds in my briefcase, some souvenirs issued by mining companies, plus others from Canada, Australia, China, and the US. But when I left Chile a couple of months ago, the person monitoring the X-ray machine stopped me and insisted I take them out and show them to her. This had never happened before, but I wrote it off to chance. Then, when I was leaving Argentina a few weeks later, the same thing happened. What was really unusual was that the inspector looked at them, took them back to his supervisor, and then asked if I had any gold coins. I didn’t, he smiled, and I went on.

What really got my attention was a few weeks later when I was leaving Mauritania, one of the world’s more backward countries. Here, I was also questioned about the silver coins. A supervisor was again called over and asked me whether I had any gold coins. Clearly, something was up.