My friend Erik Vance lives in Mexico City and writes about science. But, in the past year or so, his work covering ocean fisheries has brought him into contact with some of the fallout from the cocaine trade. That overlap lead to a recent piece for Slate, where he writes that "there's no such thing as cruelty-free cocaine". If you care about sustainability, fair trade, and the power of consumer choice to change industry practices in fishing, then you should care about those things when it comes to drugs, he writes. More provocatively, Vance likens buying coke today to donating to the Nazi party in the 1930s.