Here's an enlightening short documentary from VICE about the growing counterfeit money market in Lima, Peru. The country has taken the counterfeit crown from Colombia by producing what the US considers to be the best counterfeit notes in the world. For just a few cents per note (usually in $20s, $50s, or $100s) and the right amount of contacts, you could potentially snag yourself thousands in money that could pass in most places in the US. It's kind of scary to think about how many of these notes have flooded the US in circulation already. Have I accidentally used one of these? Who knows. But it's bad news for US buyers either way.