In the end, it was relatively old-fashioned police work that brought down Ross William Ulbricht, a 29-year-old San Francisco resident who looks a bit like Emile Hirsch in Into the Wild and is thought to be the owner and operator of online drugs marketplace, Silk Road. It was partly through mundane, archaic websites such as LinkedIn and WordPress, as well as a Gmail account, that Ulbricht came to the authorities' attention.

Like an upwardly mobile Apprentice candidate keen to impress Lord Sugar, Ulbricht just couldn't quite stop himself from boasting of a new position on LinkedIn. Operating on the deep web, using Tor software, Silk Road was the next-generation, post-WikiLeaks way to buy drugs. The shutting down of the site feels a bit like a motorboat full of old-school toughs boarding a 21st-century pirate ship run by mild-mannered nerds. It also, despite allegations that Ulbricht paid a hitman to have a Silk Road user who was threatening him killed, feels like a shame. If the allegations are true, there is absolutely no defence for that, but they are inconclusive, and in stark contrast to descriptions of Ulbricht as an idealist, a young man who wanted to make the buying and selling of drugs a cleaner, safer affair.

The end of Silk Road feels like a shame because its closure – and the arrest of Ulbricht – simply tells us that the American government has found yet another way to waste time and money on the policing of drugs. The internet, particularly the deep web, has opened up a new front in the war on drugs. You can almost imagine drug authorities getting a perverse thrill from the prospect of a new type of adversary, a new breed of law-breaker to add colour to a picture that is mostly taken up by ultra-violent cartels. In steaming into this new world the drug authorities were, yet again, doing the wrong thing expensively.

Silk Road could have ended up providing a real alternative to the cartels. It could have taken money out of their pockets and put it into the pockets of people whose only crime was to sell drugs – as opposed to people whose many crimes include mass-murder and kidnapping. When I interviewed the former drug smuggler Brian O'Dea, he told me that it was the drug authorities' decision to go after peaceful guys like him ("low hanging fruit") that led to the drug-trafficking business being dominated by violent gangs. For O'Dea in the 1980s, read Ulbricht today.

Silk Road also provided a model for how the legalised selling of drugs might work. Reports suggest that the drugs were less contaminated and that the experience of buying them was less fraught. On the one hand, that just means less awkward sitting around in cars with guys you don't really want to talk to – on the other hand, it means not being put in physical danger because you'd rather get high than get drunk.

We have to get out of the mindset of thinking that things are wrong because they are illegal. People make laws and people can change those laws. The war on drugs is hugely expensive. The criminalisation of drugs forces people to take risks they wouldn't normally take and leads to overdoses and the contamination of substances that would not otherwise cause such extreme harm. It creates addicts and it creates dealers. Silk Road showed us a way – a hugely imperfect way, it should be noted – that these things could be overcome but our lawmakers, with their focus on punishment and their refusal to accept defeat, could not see the benefit in this. Prohibition never works but it's still the order of the day.