Let me preface this with the fact that I support the shit out of drugs. Natural substances are here for our consumption.

Buying drugs on the internet, however, is fail.

Drugs are illegal. Crazy, right? When I do illegal shit, it helps if there isn't a record of it. Bitcoin is one of the most honest systems of value transmission available, that's the whole point. To make an illegal purchase on a public ledger sounds like sticking one's head in the oven to me. And this isn't just the btc blockchain that's sitting on this tasty kernel of knowledge; your isp is in on the party, or any state actor that gets a bug in his ass to trace back that tx. Like the ATF. Or the FBI. Or some other government agency with three letters, guns, and badass black suits. If you are going to buy drugs, children, buy them in person. Yes, it's more expensive, and less convenient. But that's because there is no lingering threat of prosecution indefinately after the sale what goes on in the passenger seat of that Camaro (because obviously all drug dealers own Camaros, duh), stays in the Camaro.

Unless he's an undercover. The situation may evolve a bit