In the past few months, fake cancer drugs have been found in clinics from California to Illinois. These fakes, which probably originated in China, were traded by numerous Middle Eastern and European traders, all of whom claimed they had no idea the products were fake. The U.S. Food and Drug Administration is investigating.But a more subtle and probably greater danger is that some drugs that make it to the U.S. legally simply do not work. All companies make mistakes and occasionally release drugs that don’t work properly. Sometimes negligence is the cause; witness the recent problems at the Puerto...