Pirate's Gold brand milk chocolate coins, sold in Canadian Costco stores, are imported from China and contain melamine, the same chemical that's been in the news lately for killing several babies in China.
I asked my dad, a nutritionist, what the deal is with melamine. He said it's a type of plastic (it's in formica, some whiteboards, and it's the "mel" in Melmac). Unfortunately, the most common test for the amount of protein in an item reads melamine as protein, so unscrupulous souls are adding it to milk to make the milk seem to have more protein. The human body knows damn well it's not protein, though, and protests.