The suspected mastermind behind the underground website Silk Road was convicted on narcotics and other charges for his role in orchestrating a scheme that enabled around $200m (€175m) of anonymous online drug sales using bitcoins.

The tranquility of Glen Park public library, in San Francisco, was disrupted last week by half a dozen FBI agents descending on the science-fiction section, where nerds congregate to read their emails on the free Wi-Fi.

US law enforcement authorities have shut down Silk Road, the web marketplace for illegal drugs like heroin and cocaine as well as criminal activities including murder for hire, and arrested its alleged owner, the Federal Bureau of Investigation said yesterday.